scope and limitation of the study in experimental research

How to Write Limitations of the Study (with examples)

This blog emphasizes the importance of recognizing and effectively writing about limitations in research. It discusses the types of limitations, their significance, and provides guidelines for writing about them, highlighting their role in advancing scholarly research.

Updated on August 24, 2023

No matter how well thought out, every research endeavor encounters challenges. There is simply no way to predict all possible variances throughout the process.

These uncharted boundaries and abrupt constraints are known as limitations in research . Identifying and acknowledging limitations is crucial for conducting rigorous studies. Limitations provide context and shed light on gaps in the prevailing inquiry and literature.

This article explores the importance of recognizing limitations and discusses how to write them effectively. By interpreting limitations in research and considering prevalent examples, we aim to reframe the perception from shameful mistakes to respectable revelations.

What are limitations in research?

In the clearest terms, research limitations are the practical or theoretical shortcomings of a study that are often outside of the researcher’s control . While these weaknesses limit the generalizability of a study’s conclusions, they also present a foundation for future research.

Sometimes limitations arise from tangible circumstances like time and funding constraints, or equipment and participant availability. Other times the rationale is more obscure and buried within the research design. Common types of limitations and their ramifications include:

• Theoretical: limits the scope, depth, or applicability of a study.
• Methodological: limits the quality, quantity, or diversity of the data.
• Empirical: limits the representativeness, validity, or reliability of the data.
• Analytical: limits the accuracy, completeness, or significance of the findings.
• Ethical: limits the access, consent, or confidentiality of the data.

Regardless of how, when, or why they arise, limitations are a natural part of the research process and should never be ignored . Like all other aspects, they are vital in their own purpose.

Why is identifying limitations important?

Whether to seek acceptance or avoid struggle, humans often instinctively hide flaws and mistakes. Merging this thought process into research by attempting to hide limitations, however, is a bad idea. It has the potential to negate the validity of outcomes and damage the reputation of scholars.

By identifying and addressing limitations throughout a project, researchers strengthen their arguments and curtail the chance of peer censure based on overlooked mistakes. Pointing out these flaws shows an understanding of variable limits and a scrupulous research process.

Showing awareness of and taking responsibility for a project’s boundaries and challenges validates the integrity and transparency of a researcher. It further demonstrates the researchers understand the applicable literature and have thoroughly evaluated their chosen research methods.

Presenting limitations also benefits the readers by providing context for research findings. It guides them to interpret the project’s conclusions only within the scope of very specific conditions. By allowing for an appropriate generalization of the findings that is accurately confined by research boundaries and is not too broad, limitations boost a study’s credibility .

Limitations are true assets to the research process. They highlight opportunities for future research. When researchers identify the limitations of their particular approach to a study question, they enable precise transferability and improve chances for reproducibility. 

Simply stating a project’s limitations is not adequate for spurring further research, though. To spark the interest of other researchers, these acknowledgements must come with thorough explanations regarding how the limitations affected the current study and how they can potentially be overcome with amended methods.

How to write limitations

Typically, the information about a study’s limitations is situated either at the beginning of the discussion section to provide context for readers or at the conclusion of the discussion section to acknowledge the need for further research. However, it varies depending upon the target journal or publication guidelines. 

Don’t hide your limitations

It is also important to not bury a limitation in the body of the paper unless it has a unique connection to a topic in that section. If so, it needs to be reiterated with the other limitations or at the conclusion of the discussion section. Wherever it is included in the manuscript, ensure that the limitations section is prominently positioned and clearly introduced.

While maintaining transparency by disclosing limitations means taking a comprehensive approach, it is not necessary to discuss everything that could have potentially gone wrong during the research study. If there is no commitment to investigation in the introduction, it is unnecessary to consider the issue a limitation to the research. Wholly consider the term ‘limitations’ and ask, “Did it significantly change or limit the possible outcomes?” Then, qualify the occurrence as either a limitation to include in the current manuscript or as an idea to note for other projects. 

Writing limitations

Once the limitations are concretely identified and it is decided where they will be included in the paper, researchers are ready for the writing task. Including only what is pertinent, keeping explanations detailed but concise, and employing the following guidelines is key for crafting valuable limitations:

1) Identify and describe the limitations : Clearly introduce the limitation by classifying its form and specifying its origin. For example:

• An unintentional bias encountered during data collection
• An intentional use of unplanned post-hoc data analysis

2) Explain the implications : Describe how the limitation potentially influences the study’s findings and how the validity and generalizability are subsequently impacted. Provide examples and evidence to support claims of the limitations’ effects without making excuses or exaggerating their impact. Overall, be transparent and objective in presenting the limitations, without undermining the significance of the research. 

3) Provide alternative approaches for future studies : Offer specific suggestions for potential improvements or avenues for further investigation. Demonstrate a proactive approach by encouraging future research that addresses the identified gaps and, therefore, expands the knowledge base.

Whether presenting limitations as an individual section within the manuscript or as a subtopic in the discussion area, authors should use clear headings and straightforward language to facilitate readability. There is no need to complicate limitations with jargon, computations, or complex datasets.

Examples of common limitations

Limitations are generally grouped into two categories , methodology and research process .

Methodology limitations

Methodology may include limitations due to:

• Sample size
• Lack of available or reliable data
• Lack of prior research studies on the topic
• Measure used to collect the data
• Self-reported data

The researcher is addressing how the large sample size requires a reassessment of the measures used to collect and analyze the data.

Research process limitations

Limitations during the research process may arise from:

• Access to information
• Longitudinal effects
• Cultural and other biases
• Language fluency
• Time constraints

The author is pointing out that the model’s estimates are based on potentially biased observational studies.

Final thoughts

Successfully proving theories and touting great achievements are only two very narrow goals of scholarly research. The true passion and greatest efforts of researchers comes more in the form of confronting assumptions and exploring the obscure.

In many ways, recognizing and sharing the limitations of a research study both allows for and encourages this type of discovery that continuously pushes research forward. By using limitations to provide a transparent account of the project's boundaries and to contextualize the findings, researchers pave the way for even more robust and impactful research in the future.

Charla Viera, MS

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How to Write the Scope of the Study

• By DiscoverPhDs
• August 26, 2020

What is the Scope of the Study?

The scope of the study refers to the boundaries within which your research project will be performed; this is sometimes also called the scope of research. To define the scope of the study is to define all aspects that will be considered in your research project. It is also just as important to make clear what aspects will not be covered; i.e. what is outside of the scope of the study.

Why is the Scope of the Study Important?

The scope of the study is always considered and agreed upon in the early stages of the project, before any data collection or experimental work has started. This is important because it focuses the work of the proposed study down to what is practically achievable within a given timeframe.

A well-defined research or study scope enables a researcher to give clarity to the study outcomes that are to be investigated. It makes clear why specific data points have been collected whilst others have been excluded.

Without this, it is difficult to define an end point for a research project since no limits have been defined on the work that could take place. Similarly, it can also make the approach to answering a research question too open ended.

How do you Write the Scope of the Study?

In order to write the scope of the study that you plan to perform, you must be clear on the research parameters that you will and won’t consider. These parameters usually consist of the sample size, the duration, inclusion and exclusion criteria, the methodology and any geographical or monetary constraints.

Each of these parameters will have limits placed on them so that the study can practically be performed, and the results interpreted relative to the limitations that have been defined. These parameters will also help to shape the direction of each research question you consider.

The term limitations’ is often used together with the scope of the study to describe the constraints of any parameters that are considered and also to clarify which parameters have not been considered at all. Make sure you get the balance right here between not making the scope too broad and unachievable, and it not being too restrictive, resulting in a lack of useful data.

The sample size is a commonly used parameter in the definition of the research scope. For example, a research project involving human participants may define at the start of the study that 100 participants will be recruited. This number will be determined based on an understanding of the difficulty in recruiting participants to studies and an agreement of an acceptable period of time in which to recruit this number.

Any results that are obtained by the research group can then be interpreted by others with the knowledge that the study was capped to 100 participants and an acceptance of this as a limitation of the study. In other words, it is acknowledged that recruiting 100 rather than 1,000 participants has limited the amount of data that could be collected, however this is an acceptable limitation due to the known difficulties in recruiting so many participants (e.g. the significant period of time it would take and the costs associated with this).

Example of a Scope of the Study

The follow is a (hypothetical) example of the definition of the scope of the study, with the research question investigating the impact of the COVID-19 pandemic on mental health.

Whilst the immediate negative health problems related to the COVID-19 pandemic have been well documented, the impact of the virus on the mental health (MH) of young adults (age 18-24 years) is poorly understood. The aim of this study is to report on MH changes in population group due to the pandemic.

The scope of the study is limited to recruiting 100 volunteers between the ages of 18 and 24 who will be contacted using their university email accounts. This recruitment period will last for a maximum of 2 months and will end when either 100 volunteers have been recruited or 2 months have passed. Each volunteer to the study will be asked to complete a short questionnaire in order to evaluate any changes in their MH.

From this example we can immediately see that the scope of the study has placed a constraint on the sample size to be used and/or the time frame for recruitment of volunteers. It has also introduced a limitation by only opening recruitment to people that have university emails; i.e. anyone that does not attend university will be excluded from this study.

This may be an important factor when interpreting the results of this study; the comparison of MH during the pandemic between those that do and do not attend university, is therefore outside the scope of the study here. We are also told that the methodology used to assess any changes in MH are via a questionnaire. This is a clear definition of how the outcome measure will be investigated and any other methods are not within the scope of research and their exclusion may be a limitation of the study.

The scope of the study is important to define as it enables a researcher to focus their research to within achievable parameters.

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The scope of the study is defined at the start of the study. It is used by researchers to set the boundaries and limitations within which the research study will be performed.

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The limitations of the study are those characteristics of design or methodology that impacted or influenced the interpretation of the findings from your research. Study limitations are the constraints placed on the ability to generalize from the results, to further describe applications to practice, and/or related to the utility of findings that are the result of the ways in which you initially chose to design the study or the method used to establish internal and external validity or the result of unanticipated challenges that emerged during the study.

Price, James H. and Judy Murnan. “Research Limitations and the Necessity of Reporting Them.” American Journal of Health Education 35 (2004): 66-67; Theofanidis, Dimitrios and Antigoni Fountouki. "Limitations and Delimitations in the Research Process." Perioperative Nursing 7 (September-December 2018): 155-163. .

Importance of...

Always acknowledge a study's limitations. It is far better that you identify and acknowledge your study’s limitations than to have them pointed out by your professor and have your grade lowered because you appeared to have ignored them or didn't realize they existed.

Keep in mind that acknowledgment of a study's limitations is an opportunity to make suggestions for further research. If you do connect your study's limitations to suggestions for further research, be sure to explain the ways in which these unanswered questions may become more focused because of your study.

Acknowledgment of a study's limitations also provides you with opportunities to demonstrate that you have thought critically about the research problem, understood the relevant literature published about it, and correctly assessed the methods chosen for studying the problem. A key objective of the research process is not only discovering new knowledge but also to confront assumptions and explore what we don't know.

Claiming limitations is a subjective process because you must evaluate the impact of those limitations . Don't just list key weaknesses and the magnitude of a study's limitations. To do so diminishes the validity of your research because it leaves the reader wondering whether, or in what ways, limitation(s) in your study may have impacted the results and conclusions. Limitations require a critical, overall appraisal and interpretation of their impact. You should answer the question: do these problems with errors, methods, validity, etc. eventually matter and, if so, to what extent?

Price, James H. and Judy Murnan. “Research Limitations and the Necessity of Reporting Them.” American Journal of Health Education 35 (2004): 66-67; Structure: How to Structure the Research Limitations Section of Your Dissertation. Dissertations and Theses: An Online Textbook. Laerd.com.

Descriptions of Possible Limitations

All studies have limitations . However, it is important that you restrict your discussion to limitations related to the research problem under investigation. For example, if a meta-analysis of existing literature is not a stated purpose of your research, it should not be discussed as a limitation. Do not apologize for not addressing issues that you did not promise to investigate in the introduction of your paper.

Here are examples of limitations related to methodology and the research process you may need to describe and discuss how they possibly impacted your results. Note that descriptions of limitations should be stated in the past tense because they were discovered after you completed your research.

Possible Methodological Limitations

• Sample size -- the number of the units of analysis you use in your study is dictated by the type of research problem you are investigating. Note that, if your sample size is too small, it will be difficult to find significant relationships from the data, as statistical tests normally require a larger sample size to ensure a representative distribution of the population and to be considered representative of groups of people to whom results will be generalized or transferred. Note that sample size is generally less relevant in qualitative research if explained in the context of the research problem.
• Lack of available and/or reliable data -- a lack of data or of reliable data will likely require you to limit the scope of your analysis, the size of your sample, or it can be a significant obstacle in finding a trend and a meaningful relationship. You need to not only describe these limitations but provide cogent reasons why you believe data is missing or is unreliable. However, don’t just throw up your hands in frustration; use this as an opportunity to describe a need for future research based on designing a different method for gathering data.
• Lack of prior research studies on the topic -- citing prior research studies forms the basis of your literature review and helps lay a foundation for understanding the research problem you are investigating. Depending on the currency or scope of your research topic, there may be little, if any, prior research on your topic. Before assuming this to be true, though, consult with a librarian! In cases when a librarian has confirmed that there is little or no prior research, you may be required to develop an entirely new research typology [for example, using an exploratory rather than an explanatory research design ]. Note again that discovering a limitation can serve as an important opportunity to identify new gaps in the literature and to describe the need for further research.
• Measure used to collect the data -- sometimes it is the case that, after completing your interpretation of the findings, you discover that the way in which you gathered data inhibited your ability to conduct a thorough analysis of the results. For example, you regret not including a specific question in a survey that, in retrospect, could have helped address a particular issue that emerged later in the study. Acknowledge the deficiency by stating a need for future researchers to revise the specific method for gathering data.
• Self-reported data -- whether you are relying on pre-existing data or you are conducting a qualitative research study and gathering the data yourself, self-reported data is limited by the fact that it rarely can be independently verified. In other words, you have to the accuracy of what people say, whether in interviews, focus groups, or on questionnaires, at face value. However, self-reported data can contain several potential sources of bias that you should be alert to and note as limitations. These biases become apparent if they are incongruent with data from other sources. These are: (1) selective memory [remembering or not remembering experiences or events that occurred at some point in the past]; (2) telescoping [recalling events that occurred at one time as if they occurred at another time]; (3) attribution [the act of attributing positive events and outcomes to one's own agency, but attributing negative events and outcomes to external forces]; and, (4) exaggeration [the act of representing outcomes or embellishing events as more significant than is actually suggested from other data].

Possible Limitations of the Researcher

• Access -- if your study depends on having access to people, organizations, data, or documents and, for whatever reason, access is denied or limited in some way, the reasons for this needs to be described. Also, include an explanation why being denied or limited access did not prevent you from following through on your study.
• Longitudinal effects -- unlike your professor, who can literally devote years [even a lifetime] to studying a single topic, the time available to investigate a research problem and to measure change or stability over time is constrained by the due date of your assignment. Be sure to choose a research problem that does not require an excessive amount of time to complete the literature review, apply the methodology, and gather and interpret the results. If you're unsure whether you can complete your research within the confines of the assignment's due date, talk to your professor.
• Cultural and other type of bias -- we all have biases, whether we are conscience of them or not. Bias is when a person, place, event, or thing is viewed or shown in a consistently inaccurate way. Bias is usually negative, though one can have a positive bias as well, especially if that bias reflects your reliance on research that only support your hypothesis. When proof-reading your paper, be especially critical in reviewing how you have stated a problem, selected the data to be studied, what may have been omitted, the manner in which you have ordered events, people, or places, how you have chosen to represent a person, place, or thing, to name a phenomenon, or to use possible words with a positive or negative connotation. NOTE :   If you detect bias in prior research, it must be acknowledged and you should explain what measures were taken to avoid perpetuating that bias. For example, if a previous study only used boys to examine how music education supports effective math skills, describe how your research expands the study to include girls.
• Fluency in a language -- if your research focuses , for example, on measuring the perceived value of after-school tutoring among Mexican-American ESL [English as a Second Language] students and you are not fluent in Spanish, you are limited in being able to read and interpret Spanish language research studies on the topic or to speak with these students in their primary language. This deficiency should be acknowledged.

Aguinis, Hermam and Jeffrey R. Edwards. “Methodological Wishes for the Next Decade and How to Make Wishes Come True.” Journal of Management Studies 51 (January 2014): 143-174; Brutus, Stéphane et al. "Self-Reported Limitations and Future Directions in Scholarly Reports: Analysis and Recommendations." Journal of Management 39 (January 2013): 48-75; Senunyeme, Emmanuel K. Business Research Methods. Powerpoint Presentation. Regent University of Science and Technology; ter Riet, Gerben et al. “All That Glitters Isn't Gold: A Survey on Acknowledgment of Limitations in Biomedical Studies.” PLOS One 8 (November 2013): 1-6.

Structure and Writing Style

Information about the limitations of your study are generally placed either at the beginning of the discussion section of your paper so the reader knows and understands the limitations before reading the rest of your analysis of the findings, or, the limitations are outlined at the conclusion of the discussion section as an acknowledgement of the need for further study. Statements about a study's limitations should not be buried in the body [middle] of the discussion section unless a limitation is specific to something covered in that part of the paper. If this is the case, though, the limitation should be reiterated at the conclusion of the section.

If you determine that your study is seriously flawed due to important limitations , such as, an inability to acquire critical data, consider reframing it as an exploratory study intended to lay the groundwork for a more complete research study in the future. Be sure, though, to specifically explain the ways that these flaws can be successfully overcome in a new study.

But, do not use this as an excuse for not developing a thorough research paper! Review the tab in this guide for developing a research topic . If serious limitations exist, it generally indicates a likelihood that your research problem is too narrowly defined or that the issue or event under study is too recent and, thus, very little research has been written about it. If serious limitations do emerge, consult with your professor about possible ways to overcome them or how to revise your study.

When discussing the limitations of your research, be sure to:

• Describe each limitation in detailed but concise terms;
• Explain why each limitation exists;
• Provide the reasons why each limitation could not be overcome using the method(s) chosen to acquire or gather the data [cite to other studies that had similar problems when possible];
• Assess the impact of each limitation in relation to the overall findings and conclusions of your study; and,
• If appropriate, describe how these limitations could point to the need for further research.

Remember that the method you chose may be the source of a significant limitation that has emerged during your interpretation of the results [for example, you didn't interview a group of people that you later wish you had]. If this is the case, don't panic. Acknowledge it, and explain how applying a different or more robust methodology might address the research problem more effectively in a future study. A underlying goal of scholarly research is not only to show what works, but to demonstrate what doesn't work or what needs further clarification.

Aguinis, Hermam and Jeffrey R. Edwards. “Methodological Wishes for the Next Decade and How to Make Wishes Come True.” Journal of Management Studies 51 (January 2014): 143-174; Brutus, Stéphane et al. "Self-Reported Limitations and Future Directions in Scholarly Reports: Analysis and Recommendations." Journal of Management 39 (January 2013): 48-75; Ioannidis, John P.A. "Limitations are not Properly Acknowledged in the Scientific Literature." Journal of Clinical Epidemiology 60 (2007): 324-329; Pasek, Josh. Writing the Empirical Social Science Research Paper: A Guide for the Perplexed. January 24, 2012. Academia.edu; Structure: How to Structure the Research Limitations Section of Your Dissertation. Dissertations and Theses: An Online Textbook. Laerd.com; What Is an Academic Paper? Institute for Writing Rhetoric. Dartmouth College; Writing the Experimental Report: Methods, Results, and Discussion. The Writing Lab and The OWL. Purdue University.

Writing Tip

Don't Inflate the Importance of Your Findings!

After all the hard work and long hours devoted to writing your research paper, it is easy to get carried away with attributing unwarranted importance to what you’ve done. We all want our academic work to be viewed as excellent and worthy of a good grade, but it is important that you understand and openly acknowledge the limitations of your study. Inflating the importance of your study's findings could be perceived by your readers as an attempt hide its flaws or encourage a biased interpretation of the results. A small measure of humility goes a long way!

Another Writing Tip

Negative Results are Not a Limitation!

Negative evidence refers to findings that unexpectedly challenge rather than support your hypothesis. If you didn't get the results you anticipated, it may mean your hypothesis was incorrect and needs to be reformulated. Or, perhaps you have stumbled onto something unexpected that warrants further study. Moreover, the absence of an effect may be very telling in many situations, particularly in experimental research designs. In any case, your results may very well be of importance to others even though they did not support your hypothesis. Do not fall into the trap of thinking that results contrary to what you expected is a limitation to your study. If you carried out the research well, they are simply your results and only require additional interpretation.

Lewis, George H. and Jonathan F. Lewis. “The Dog in the Night-Time: Negative Evidence in Social Research.” The British Journal of Sociology 31 (December 1980): 544-558.

Yet Another Writing Tip

Sample Size Limitations in Qualitative Research

Sample sizes are typically smaller in qualitative research because, as the study goes on, acquiring more data does not necessarily lead to more information. This is because one occurrence of a piece of data, or a code, is all that is necessary to ensure that it becomes part of the analysis framework. However, it remains true that sample sizes that are too small cannot adequately support claims of having achieved valid conclusions and sample sizes that are too large do not permit the deep, naturalistic, and inductive analysis that defines qualitative inquiry. Determining adequate sample size in qualitative research is ultimately a matter of judgment and experience in evaluating the quality of the information collected against the uses to which it will be applied and the particular research method and purposeful sampling strategy employed. If the sample size is found to be a limitation, it may reflect your judgment about the methodological technique chosen [e.g., single life history study versus focus group interviews] rather than the number of respondents used.

Boddy, Clive Roland. "Sample Size for Qualitative Research." Qualitative Market Research: An International Journal 19 (2016): 426-432; Huberman, A. Michael and Matthew B. Miles. "Data Management and Analysis Methods." In Handbook of Qualitative Research . Norman K. Denzin and Yvonna S. Lincoln, eds. (Thousand Oaks, CA: Sage, 1994), pp. 428-444; Blaikie, Norman. "Confounding Issues Related to Determining Sample Size in Qualitative Research." International Journal of Social Research Methodology 21 (2018): 635-641; Oppong, Steward Harrison. "The Problem of Sampling in qualitative Research." Asian Journal of Management Sciences and Education 2 (2013): 202-210.

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Experimental Research

• First Online: 25 February 2021

Cite this chapter

• C. George Thomas 2  

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Experiments are part of the scientific method that helps to decide the fate of two or more competing hypotheses or explanations on a phenomenon. The term ‘experiment’ arises from Latin, Experiri, which means, ‘to try’. The knowledge accrues from experiments differs from other types of knowledge in that it is always shaped upon observation or experience. In other words, experiments generate empirical knowledge. In fact, the emphasis on experimentation in the sixteenth and seventeenth centuries for establishing causal relationships for various phenomena happening in nature heralded the resurgence of modern science from its roots in ancient philosophy spearheaded by great Greek philosophers such as Aristotle.

The strongest arguments prove nothing so long as the conclusions are not verified by experience. Experimental science is the queen of sciences and the goal of all speculation . Roger Bacon (1214–1294)

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Thomas, C.G. (2021). Experimental Research. In: Research Methodology and Scientific Writing . Springer, Cham. https://doi.org/10.1007/978-3-030-64865-7_5

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DOI : https://doi.org/10.1007/978-3-030-64865-7_5

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Publisher Name : Springer, Cham

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Online ISBN : 978-3-030-64865-7

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Exploring Scope and Delimitation in Academic Research

Academic research is a meticulous process that requires precise planning and clear boundaries. Two pivotal components in this process are the scope and delimitations of the study. The definitions and establishment of these parameters are instrumental in ensuring that the research is effective, manageable, and yields relevant results.

The "scope" of a research project refers to the areas that the study will cover. It is the breadth and depth of the investigation. It defines the subject matter, the geographical location, the time frame, and the issues that the study will explore. Essentially, the scope delineates what the researcher aims to cover in the study.

On the other hand, "delimitations" are the boundaries or limitations set by the researcher. They define what the study will not include. Delimitations could involve the choice of research methodology , the selection of respondents, the duration of the study, and more. They help in confining the study to a manageable size while excluding peripheral elements.

Understanding and correctly implementing scope and delimitations are vital to ensuring your research is well-defined and focused, facilitating higher accuracy and relevancy in your findings.

Importance of scope in research

"Scope" in research refers to the comprehensive extent of study—it outlines the parameters of what will be explored and addressed. It defines the topic of the research , the geographical region under study, the timeframe considered, and the issues that the study will address. The scope of a research project is vital because it determines the depth and breadth of your investigation.

Defining the scope of research is a fundamental step in the research process for several reasons. First, it provides a roadmap for the study, giving the researcher clear guidelines about what to include and exclude. Without a well-defined scope, research can become unmanageably vast or lose its focus.

Second, the scope ensures the research's relevance and applicability. It helps the researcher maintain a tight focus on the study's central question , ensuring that all aspects of the research contribute to answering this question. This focus aids in avoiding irrelevant diversions that could dilute the final conclusions.

Finally, a well-defined scope can help ensure the efficient use of resources. Research involves considerable time, effort, and often financial resources. By providing clear boundaries, the scope ensures these resources are utilized effectively without wasted effort on peripheral issues.

Suppose a research study is looking at the impacts of social media usage on mental health. If the scope is too broad—like examining all social media platforms' effects on all demographic groups worldwide—then the research can quickly become unwieldy and hard to manage. It would involve vast amounts of data, requiring considerable time, resources, and computational power to analyze effectively.

However, if the scope is narrowed down—such as investigating the impact of Instagram usage on the mental health of teenagers in a specific city over the past five years—the research becomes far more manageable. This specific focus allows for a more in-depth analysis and likely will provide more meaningful, actionable results. This example illustrates the importance of appropriately defining the scope of research for its successful execution.

Determining the scope of your research

Setting the scope of your research project is a critical and delicate task. Below are steps, tips, and common mistakes to avoid when determining the scope of your research:

Steps to define the scope

• Identify Your Topic: The first step involves identifying and understanding your research topic. This knowledge will serve as a basis for determining the breadth and depth of your study.
• Define Your Research Questions: The research questions are the heart of your study. They will help you determine the specific areas your research should cover.
• Establish Boundaries: Clearly establish the geographical, temporal, and topical boundaries of your research. These boundaries will guide the range of your study.
• Choose Your Methodology: Decide on the research methods you will use as these will directly impact the scope of your study.

Tips for a manageable scope

• Stay Focused: Stay concentrated on your research questions. Do not stray into areas that aren't directly relevant.
• Be Realistic: Consider the resources (time, money, manpower) available. Ensure your scope is feasible given these resources.
• Seek Guidance: Consult with your academic advisor or peers for feedback on your proposed scope.

Common mistakes to avoid

• Overly Broad Scope: Avoid setting an overly broad scope which could result in an unmanageable and unfocused study.
• Too Narrow Scope: Conversely, a scope that is too narrow may miss important aspects of the research topic.
• Ignoring Resources: Not taking into account available resources when setting the scope can lead to a project that is impossible to complete.

Defining the scope of your research is a delicate balance, requiring careful consideration of your research questions, resources, and the depth and breadth of investigation needed to answer these questions effectively.

Importance of delimitations in research

In the context of academic research, "delimitations" refers to the choices made by the researcher which define the boundaries of the study. These are the variables that lead the researcher to narrow the scope of the study from its potential vastness to a manageable size.

Delimitations might include the geographic area where the study is confined, the participants involved in the study, the methodology used, the time period considered, or the specific incidents or aspects the study will focus on. Essentially, delimitations are the self-imposed limitations on the scope of the study.

Defining the delimitations of a research project is crucial for several reasons. Firstly, they establish the context or setting in which the study occurs. This, in turn, allows for the work to be reproduced in a similar context for verification or refutation in future studies.

Secondly, delimitations provide a way to narrow the scope of the research to a manageable size, thus avoiding the pitfall of an overly ambitious project. They help researchers to stay focused on the main research questions and prevent diversion into irrelevant aspects.

Finally, clearly defined delimitations enhance the credibility of the research. They offer transparency about the research design and methodology, which adds to the validity of the results.

For instance, in a research study examining the impact of technology on student achievement in a certain district, examples of delimitations might include focusing only on public schools, considering only high school students, and confining the study to a particular school year. These choices help to focus the research and ensure its manageability. Therefore, delimitations play a pivotal role in structuring and guiding an effective and efficient research study.

Setting delimitations for your research

Establishing appropriate delimitations for your research project is an important part of research design. Here are some steps, guidelines, and common mistakes to consider when setting your research delimitations:

Steps to establish delimitations

• Identify the boundaries: Begin by deciding the geographical region, time period, and subject matter your research will cover.
• Determine Your Research Population: Identify the specific population your study will focus on. This could be based on age, profession, geographical location, etc.
• Choose Your Research Methods: Decide the specific methods you will use to collect and analyze data, as these decisions will also set limitations on your study.

Guidelines for choosing delimitations

• Align with Your Research Objectives: The delimitations should be in line with your research questions and objectives. They should help focus your study without detracting from its goals.
• Be Practical: Consider the resources available, including time, funds, and access to data. Your delimitations should be feasible given these constraints.
• Seek Input: Consult with your research advisor or peers. Their feedback can help ensure your delimitations are appropriate and well thought out.

Common errors to avoid:

• Unrealistic Delimitations: Be wary of setting delimitations that are too stringent or ambitious to be feasible given your resources and timeframe.
• Undefined Delimitations: Avoid leaving your delimitations vague or undefined. This can lead to scope creep, where your project expands beyond its initial plan, making it unmanageable.
• Ignoring Delimitations: Once set, stick to your delimitations. Deviating from them can lead to a loss of focus and can compromise the integrity of your results.

Setting delimitations is a crucial step in research planning. Properly defined delimitations can make your research project more manageable, maintain your focus, and ensure the effective use of your resources.

The interplay between scope and delimitations

The relationship between scope and delimitations in academic research is a dynamic and interdependent one. Each aspect serves to shape and refine the other, ultimately leading to a focused, feasible, and effective research design.

The scope of a research project describes the breadth and depth of the investigation—what it aims to cover and how far it intends to delve into the subject matter. The delimitations, on the other hand, identify the boundaries and constraints of the study—what it will not cover.

As such, the scope and delimitations of a research study are intimately connected. When the scope of a study is broad, the delimitations must be carefully considered to ensure the project remains manageable and focused. Conversely, when the scope is narrow, the delimitations might be less constraining, but they still play a critical role in defining the specificity of the research.

Balancing the scope and delimitations is crucial for an efficient research design. Too broad a scope without carefully defined delimitations can lead to a study that is unwieldy and lacks depth. On the other hand, a very narrow scope with overly rigid delimitations might result in a study that overlooks important aspects of the research topic.

Thus, researchers must strive to maintain a balance—establishing a scope that is wide enough to fully explore the research topic, but also setting appropriate delimitations to ensure the study remains feasible and focused. In doing so, the research will be well-structured and yield meaningful, relevant findings.

Role of scope and delimitations in research validity

Scope and delimitations are fundamental aspects of research design that directly influence the validity, reliability, and replicability of a study.

Research validity refers to the degree to which a study accurately reflects or measures the concept that the researcher intends to investigate. A well-defined scope is critical to research validity because it clearly delineates what the study will cover. This clear definition ensures that the research focuses on relevant aspects of the topic and that the findings accurately reflect the concept under investigation.

Similarly, carefully thought-out delimitations contribute to research validity by identifying what the study will not cover. This clarity helps to prevent the study from straying into irrelevant areas, ensuring that the research stays focused and relevant.

In addition to contributing to research validity, scope and delimitations also influence the reliability and replicability of a study. Reliability refers to the consistency of a study's results, while replicability refers to the ability of other researchers to repeat the study and obtain similar results.

A clearly defined scope makes a study more reliable by providing a detailed outline of the areas covered by the research. This clarity makes it more likely that the study will produce consistent results. Moreover, clearly defined delimitations enhance the replicability of a study by providing explicit boundaries for the research, which makes it easier for other researchers to repeat the study in a similar context.

In summary, a well-defined scope and carefully thought-out delimitations contribute significantly to the validity, reliability, and replicability of academic research. They ensure that the research is focused, that the findings are relevant and accurate, and that the study can be reliably repeated by other researchers.

Examples of scope and delimitation in well-known research

• The Milgram Experiment: Stanley Milgram's famous psychology experiment sought to understand obedience to authority figures. The scope of this study was clearly defined—it focused on how far individuals would go in obeying an instruction if it involved harming another person. However, delimitations were set to ensure manageability. Participants were delimited to male individuals, and the experiment was confined to a controlled laboratory setting. These delimitations allowed Milgram to manage the research effectively while maintaining the depth of his study on human behavior.
• The Framingham Heart Study: This ongoing cardiovascular study began in 1948 and is aimed at identifying common factors that contribute to cardiovascular disease. The scope of the research is broad, covering many aspects of lifestyle, medical history, and physical characteristics. However, the study set clear delimitations: it initially only involved adult residents of Framingham, Massachusetts. This geographical delimitation made this broad-scope study manageable and eventually yielded influential results that shaped our understanding of heart disease.
• The Marshmallow Test: This well-known study by Walter Mischel explored delayed gratification in children. The scope was clearly defined: the study aimed to understand the ability of children to delay gratification and how it related to future success. The delimitations of the study included the age of the participants (preschool children), the setting (a controlled experiment with a treat), and the measure of future success (academic achievement, ability to cope with stress, etc.). These delimitations helped keep the study focused and manageable.

In all these examples, the researchers set a clear scope to outline the focus of their studies and used delimitations to restrict the boundaries. This balance between scope and delimitation was key in conducting successful and influential research.

In academic research, defining the scope and delimitations is a pivotal step in designing a robust and effective study. The scope outlines the breadth and depth of the investigation, offering a clear direction for the research. Meanwhile, delimitations set the boundaries of the study, ensuring that the research remains focused and manageable. Together, they play a crucial role in enhancing the validity, reliability, and replicability of a study.

Understanding the interplay between scope and delimitations is key to conducting efficient research. A well-defined scope paired with thoughtfully set delimitations contribute to a study's feasibility and its potential to yield meaningful and applicable results. Mistakes in setting the scope and delimitations can lead to unwieldy, unfocused research or a study that overlooks important aspects of a research question.

Reviewing famous studies, like the Milgram Experiment, the Framingham Heart Study, and the Marshmallow Test, we observe how a balanced approach to setting scope and delimitations can result in influential and valuable findings. Therefore, researchers should give careful thought to defining the scope and delimitations of their studies, keeping in mind their research questions, available resources, and the need for balance between breadth and focus. By doing so, they pave the way for successful and impactful research outcomes.

Header image by Kübra Arslaner .

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Need an academic editor before submitting your work?

Writing Limitations of Research Study — 4 Reasons Why It Is Important!

It is not unusual for researchers to come across the term limitations of research during their academic paper writing. More often this is interpreted as something terrible. However, when it comes to research study, limitations can help structure the research study better. Therefore, do not underestimate significance of limitations of research study.

Allow us to take you through the context of how to evaluate the limits of your research and conclude an impactful relevance to your results.

Table of Contents

What Are the Limitations of a Research Study?

Every research has its limit and these limitations arise due to restrictions in methodology or research design.  This could impact your entire research or the research paper you wish to publish. Unfortunately, most researchers choose not to discuss their limitations of research fearing it will affect the value of their article in the eyes of readers.

However, it is very important to discuss your study limitations and show it to your target audience (other researchers, journal editors, peer reviewers etc.). It is very important that you provide an explanation of how your research limitations may affect the conclusions and opinions drawn from your research. Moreover, when as an author you state the limitations of research, it shows that you have investigated all the weaknesses of your study and have a deep understanding of the subject. Being honest could impress your readers and mark your study as a sincere effort in research.

Why and Where Should You Include the Research Limitations?

The main goal of your research is to address your research objectives. Conduct experiments, get results and explain those results, and finally justify your research question . It is best to mention the limitations of research in the discussion paragraph of your research article.

At the very beginning of this paragraph, immediately after highlighting the strengths of the research methodology, you should write down your limitations. You can discuss specific points from your research limitations as suggestions for further research in the conclusion of your thesis.

1. Common Limitations of the Researchers

Limitations that are related to the researcher must be mentioned. This will help you gain transparency with your readers. Furthermore, you could provide suggestions on decreasing these limitations in you and your future studies.

2. Limited Access to Information

Your work may involve some institutions and individuals in research, and sometimes you may have problems accessing these institutions. Therefore, you need to redesign and rewrite your work. You must explain your readers the reason for limited access.

3. Limited Time

All researchers are bound by their deadlines when it comes to completing their studies. Sometimes, time constraints can affect your research negatively. However, the best practice is to acknowledge it and mention a requirement for future study to solve the research problem in a better way.

4. Conflict over Biased Views and Personal Issues

Biased views can affect the research. In fact, researchers end up choosing only those results and data that support their main argument, keeping aside the other loose ends of the research.

Types of Limitations of Research

Before beginning your research study, know that there are certain limitations to what you are testing or possible research results. There are different types that researchers may encounter, and they all have unique characteristics, such as:

1. Research Design Limitations

Certain restrictions on your research or available procedures may affect your final results or research outputs. You may have formulated research goals and objectives too broadly. However, this can help you understand how you can narrow down the formulation of research goals and objectives, thereby increasing the focus of your study.

2. Impact Limitations

Even if your research has excellent statistics and a strong design, it can suffer from the influence of the following factors:

• Presence of increasing findings as researched
• Being population specific
• A strong regional focus.

3. Data or statistical limitations

In some cases, it is impossible to collect sufficient data for research or very difficult to get access to the data. This could lead to incomplete conclusion to your study. Moreover, this insufficiency in data could be the outcome of your study design. The unclear, shabby research outline could produce more problems in interpreting your findings.

How to Correctly Structure Your Research Limitations?

There are strict guidelines for narrowing down research questions, wherein you could justify and explain potential weaknesses of your academic paper. You could go through these basic steps to get a well-structured clarity of research limitations:

• Declare that you wish to identify your limitations of research and explain their importance,
• Provide the necessary depth, explain their nature, and justify your study choices.
• Write how you are suggesting that it is possible to overcome them in the future.

In this section, your readers will see that you are aware of the potential weaknesses in your business, understand them and offer effective solutions, and it will positively strengthen your article as you clarify all limitations of research to your target audience.

Know that you cannot be perfect and there is no individual without flaws. You could use the limitations of research as a great opportunity to take on a new challenge and improve the future of research. In a typical academic paper, research limitations may relate to:

1. Formulating your goals and objectives

If you formulate goals and objectives too broadly, your work will have some shortcomings. In this case, specify effective methods or ways to narrow down the formula of goals and aim to increase your level of study focus.

2. Application of your data collection methods in research

If you do not have experience in primary data collection, there is a risk that there will be flaws in the implementation of your methods. It is necessary to accept this, and learn and educate yourself to understand data collection methods.

3. Sample sizes

This depends on the nature of problem you choose. Sample size is of a greater importance in quantitative studies as opposed to qualitative ones. If your sample size is too small, statistical tests cannot identify significant relationships or connections within a given data set.

You could point out that other researchers should base the same study on a larger sample size to get more accurate results.

4. The absence of previous studies in the field you have chosen

Writing a literature review is an important step in any scientific study because it helps researchers determine the scope of current work in the chosen field. It is a major foundation for any researcher who must use them to achieve a set of specific goals or objectives.

However, if you are focused on the most current and evolving research problem or a very narrow research problem, there may be very little prior research on your topic. For example, if you chose to explore the role of Bitcoin as the currency of the future, you may not find tons of scientific papers addressing the research problem as Bitcoins are only a new phenomenon.

It is important that you learn to identify research limitations examples at each step. Whatever field you choose, feel free to add the shortcoming of your work. This is mainly because you do not have many years of experience writing scientific papers or completing complex work. Therefore, the depth and scope of your discussions may be compromised at different levels compared to academics with a lot of expertise. Include specific points from limitations of research. Use them as suggestions for the future.

Have you ever faced a challenge of writing the limitations of research study in your paper? How did you overcome it? What ways did you follow? Were they beneficial? Let us know in the comments below!

Frequently Asked Questions

Setting limitations in our study helps to clarify the outcomes drawn from our research and enhance understanding of the subject. Moreover, it shows that the author has investigated all the weaknesses in the study.

Scope is the range and limitations of a research project which are set to define the boundaries of a project. Limitations are the impacts on the overall study due to the constraints on the research design.

Limitation in research is an impact of a constraint on the research design in the overall study. They are the flaws or weaknesses in the study, which may influence the outcome of the research.

1. Limitations in research can be written as follows: Formulate your goals and objectives 2. Analyze the chosen data collection method and the sample sizes 3. Identify your limitations of research and explain their importance 4. Provide the necessary depth, explain their nature, and justify your study choices 5. Write how you are suggesting that it is possible to overcome them in the future

Excellent article ,,,it has helped me big

This is very helpful information. It has given me an insight on how to go about my study limitations.

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Home » Limitations in Research – Types, Examples and Writing Guide

Limitations in Research – Types, Examples and Writing Guide

Table of Contents

Limitations in Research

Limitations in research refer to the factors that may affect the results, conclusions , and generalizability of a study. These limitations can arise from various sources, such as the design of the study, the sampling methods used, the measurement tools employed, and the limitations of the data analysis techniques.

Types of Limitations in Research

Types of Limitations in Research are as follows:

Sample Size Limitations

This refers to the size of the group of people or subjects that are being studied. If the sample size is too small, then the results may not be representative of the population being studied. This can lead to a lack of generalizability of the results.

Time Limitations

Time limitations can be a constraint on the research process . This could mean that the study is unable to be conducted for a long enough period of time to observe the long-term effects of an intervention, or to collect enough data to draw accurate conclusions.

Selection Bias

This refers to a type of bias that can occur when the selection of participants in a study is not random. This can lead to a biased sample that is not representative of the population being studied.

Confounding Variables

Confounding variables are factors that can influence the outcome of a study, but are not being measured or controlled for. These can lead to inaccurate conclusions or a lack of clarity in the results.

Measurement Error

This refers to inaccuracies in the measurement of variables, such as using a faulty instrument or scale. This can lead to inaccurate results or a lack of validity in the study.

Ethical Limitations

Ethical limitations refer to the ethical constraints placed on research studies. For example, certain studies may not be allowed to be conducted due to ethical concerns, such as studies that involve harm to participants.

Examples of Limitations in Research

Some Examples of Limitations in Research are as follows:

Research Title: “The Effectiveness of Machine Learning Algorithms in Predicting Customer Behavior”

Limitations:

• The study only considered a limited number of machine learning algorithms and did not explore the effectiveness of other algorithms.
• The study used a specific dataset, which may not be representative of all customer behaviors or demographics.
• The study did not consider the potential ethical implications of using machine learning algorithms in predicting customer behavior.

Research Title: “The Impact of Online Learning on Student Performance in Computer Science Courses”

• The study was conducted during the COVID-19 pandemic, which may have affected the results due to the unique circumstances of remote learning.
• The study only included students from a single university, which may limit the generalizability of the findings to other institutions.
• The study did not consider the impact of individual differences, such as prior knowledge or motivation, on student performance in online learning environments.

Research Title: “The Effect of Gamification on User Engagement in Mobile Health Applications”

• The study only tested a specific gamification strategy and did not explore the effectiveness of other gamification techniques.
• The study relied on self-reported measures of user engagement, which may be subject to social desirability bias or measurement errors.
• The study only included a specific demographic group (e.g., young adults) and may not be generalizable to other populations with different preferences or needs.

How to Write Limitations in Research

When writing about the limitations of a research study, it is important to be honest and clear about the potential weaknesses of your work. Here are some tips for writing about limitations in research:

• Identify the limitations: Start by identifying the potential limitations of your research. These may include sample size, selection bias, measurement error, or other issues that could affect the validity and reliability of your findings.
• Be honest and objective: When describing the limitations of your research, be honest and objective. Do not try to minimize or downplay the limitations, but also do not exaggerate them. Be clear and concise in your description of the limitations.
• Provide context: It is important to provide context for the limitations of your research. For example, if your sample size was small, explain why this was the case and how it may have affected your results. Providing context can help readers understand the limitations in a broader context.
• Discuss implications : Discuss the implications of the limitations for your research findings. For example, if there was a selection bias in your sample, explain how this may have affected the generalizability of your findings. This can help readers understand the limitations in terms of their impact on the overall validity of your research.
• Provide suggestions for future research : Finally, provide suggestions for future research that can address the limitations of your study. This can help readers understand how your research fits into the broader field and can provide a roadmap for future studies.

Purpose of Limitations in Research

There are several purposes of limitations in research. Here are some of the most important ones:

• To acknowledge the boundaries of the study : Limitations help to define the scope of the research project and set realistic expectations for the findings. They can help to clarify what the study is not intended to address.
• To identify potential sources of bias: Limitations can help researchers identify potential sources of bias in their research design, data collection, or analysis. This can help to improve the validity and reliability of the findings.
• To provide opportunities for future research: Limitations can highlight areas for future research and suggest avenues for further exploration. This can help to advance knowledge in a particular field.
• To demonstrate transparency and accountability: By acknowledging the limitations of their research, researchers can demonstrate transparency and accountability to their readers, peers, and funders. This can help to build trust and credibility in the research community.
• To encourage critical thinking: Limitations can encourage readers to critically evaluate the study’s findings and consider alternative explanations or interpretations. This can help to promote a more nuanced and sophisticated understanding of the topic under investigation.

When to Write Limitations in Research

Limitations should be included in research when they help to provide a more complete understanding of the study’s results and implications. A limitation is any factor that could potentially impact the accuracy, reliability, or generalizability of the study’s findings.

It is important to identify and discuss limitations in research because doing so helps to ensure that the results are interpreted appropriately and that any conclusions drawn are supported by the available evidence. Limitations can also suggest areas for future research, highlight potential biases or confounding factors that may have affected the results, and provide context for the study’s findings.

Generally, limitations should be discussed in the conclusion section of a research paper or thesis, although they may also be mentioned in other sections, such as the introduction or methods. The specific limitations that are discussed will depend on the nature of the study, the research question being investigated, and the data that was collected.

Examples of limitations that might be discussed in research include sample size limitations, data collection methods, the validity and reliability of measures used, and potential biases or confounding factors that could have affected the results. It is important to note that limitations should not be used as a justification for poor research design or methodology, but rather as a way to enhance the understanding and interpretation of the study’s findings.

Importance of Limitations in Research

Here are some reasons why limitations are important in research:

• Enhances the credibility of research: Limitations highlight the potential weaknesses and threats to validity, which helps readers to understand the scope and boundaries of the study. This improves the credibility of research by acknowledging its limitations and providing a clear picture of what can and cannot be concluded from the study.
• Facilitates replication: By highlighting the limitations, researchers can provide detailed information about the study’s methodology, data collection, and analysis. This information helps other researchers to replicate the study and test the validity of the findings, which enhances the reliability of research.
• Guides future research : Limitations provide insights into areas for future research by identifying gaps or areas that require further investigation. This can help researchers to design more comprehensive and effective studies that build on existing knowledge.
• Provides a balanced view: Limitations help to provide a balanced view of the research by highlighting both strengths and weaknesses. This ensures that readers have a clear understanding of the study’s limitations and can make informed decisions about the generalizability and applicability of the findings.

Advantages of Limitations in Research

Here are some potential advantages of limitations in research:

• Focus : Limitations can help researchers focus their study on a specific area or population, which can make the research more relevant and useful.
• Realism : Limitations can make a study more realistic by reflecting the practical constraints and challenges of conducting research in the real world.
• Innovation : Limitations can spur researchers to be more innovative and creative in their research design and methodology, as they search for ways to work around the limitations.
• Rigor : Limitations can actually increase the rigor and credibility of a study, as researchers are forced to carefully consider the potential sources of bias and error, and address them to the best of their abilities.
• Generalizability : Limitations can actually improve the generalizability of a study by ensuring that it is not overly focused on a specific sample or situation, and that the results can be applied more broadly.

About the author

Muhammad Hassan

Researcher, Academic Writer, Web developer

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How to present limitations in research

Last updated

30 January 2024

Reviewed by

Limitations don’t invalidate or diminish your results, but it’s best to acknowledge them. This will enable you to address any questions your study failed to answer because of them.

In this guide, learn how to recognize, present, and overcome limitations in research.

• What is a research limitation?

Research limitations are weaknesses in your research design or execution that may have impacted outcomes and conclusions. Uncovering limitations doesn’t necessarily indicate poor research design—it just means you encountered challenges you couldn’t have anticipated that limited your research efforts.

Does basic research have limitations?

Basic research aims to provide more information about your research topic. It requires the same standard research methodology and data collection efforts as any other research type, and it can also have limitations.

• Common research limitations

Researchers encounter common limitations when embarking on a study. Limitations can occur in relation to the methods you apply or the research process you design. They could also be connected to you as the researcher.

Methodology limitations

Not having access to data or reliable information can impact the methods used to facilitate your research. A lack of data or reliability may limit the parameters of your study area and the extent of your exploration.

Your sample size may also be affected because you won’t have any direction on how big or small it should be and who or what you should include. Having too few participants won’t adequately represent the population or groups of people needed to draw meaningful conclusions.

Research process limitations

The study’s design can impose constraints on the process. For example, as you’re conducting the research, issues may arise that don’t conform to the data collection methodology you developed. You may not realize until well into the process that you should have incorporated more specific questions or comprehensive experiments to generate the data you need to have confidence in your results.

Constraints on resources can also have an impact. Being limited on participants or participation incentives may limit your sample sizes. Insufficient tools, equipment, and materials to conduct a thorough study may also be a factor.

Common researcher limitations

Here are some of the common researcher limitations you may encounter:

Time: some research areas require multi-year longitudinal approaches, but you might not be able to dedicate that much time. Imagine you want to measure how much memory a person loses as they age. This may involve conducting multiple tests on a sample of participants over 20–30 years, which may be impossible.

Bias: researchers can consciously or unconsciously apply bias to their research. Biases can contribute to relying on research sources and methodologies that will only support your beliefs about the research you’re embarking on. You might also omit relevant issues or participants from the scope of your study because of your biases.

Limited access to data : you may need to pay to access specific databases or journals that would be helpful to your research process. You might also need to gain information from certain people or organizations but have limited access to them. These cases require readjusting your process and explaining why your findings are still reliable.

• Why is it important to identify limitations?

Identifying limitations adds credibility to research and provides a deeper understanding of how you arrived at your conclusions.

Constraints may have prevented you from collecting specific data or information you hoped would prove or disprove your hypothesis or provide a more comprehensive understanding of your research topic.

However, identifying the limitations contributing to your conclusions can inspire further research efforts that help gather more substantial information and data.

• Where to put limitations in a research paper

A research paper is broken up into different sections that appear in the following order:

Introduction

Methodology

The discussion portion of your paper explores your findings and puts them in the context of the overall research. Either place research limitations at the beginning of the discussion section before the analysis of your findings or at the end of the section to indicate that further research needs to be pursued.

What not to include in the limitations section

Evidence that doesn’t support your hypothesis is not a limitation, so you shouldn’t include it in the limitation section. Don’t just list limitations and their degree of severity without further explanation.

• How to present limitations

You’ll want to present the limitations of your study in a way that doesn’t diminish the validity of your research and leave the reader wondering if your results and conclusions have been compromised.

Include only the limitations that directly relate to and impact how you addressed your research questions. Following a specific format enables the reader to develop an understanding of the weaknesses within the context of your findings without doubting the quality and integrity of your research.

Identify the limitations specific to your study

You don’t have to identify every possible limitation that might have occurred during your research process. Only identify those that may have influenced the quality of your findings and your ability to answer your research question.

Explain study limitations in detail

This explanation should be the most significant portion of your limitation section.

Link each limitation with an interpretation and appraisal of their impact on the study. You’ll have to evaluate and explain whether the error, method, or validity issues influenced the study’s outcome and how.

Propose a direction for future studies and present alternatives

In this section, suggest how researchers can avoid the pitfalls you experienced during your research process.

If an issue with methodology was a limitation, propose alternate methods that may help with a smoother and more conclusive research project. Discuss the pros and cons of your alternate recommendation.

Describe steps taken to minimize each limitation

You probably took steps to try to address or mitigate limitations when you noticed them throughout the course of your research project. Describe these steps in the limitation section.

• Limitation example

“Approaches like stem cell transplantation and vaccination in AD [Alzheimer’s disease] work on a cellular or molecular level in the laboratory. However, translation into clinical settings will remain a challenge for the next decade.”

The authors are saying that even though these methods showed promise in helping people with memory loss when conducted in the lab (in other words, using animal studies), more studies are needed. These may be controlled clinical trials, for example. 

However, the short life span of stem cells outside the lab and the vaccination’s severe inflammatory side effects are limitations. Researchers won’t be able to conduct clinical trials until these issues are overcome.

• How to overcome limitations in research

You’ve already started on the road to overcoming limitations in research by acknowledging that they exist. However, you need to ensure readers don’t mistake weaknesses for errors within your research design.

To do this, you’ll need to justify and explain your rationale for the methods, research design, and analysis tools you chose and how you noticed they may have presented limitations.

Your readers need to know that even when limitations presented themselves, you followed best practices and the ethical standards of your field. You didn’t violate any rules and regulations during your research process.

You’ll also want to reinforce the validity of your conclusions and results with multiple sources, methods, and perspectives. This prevents readers from assuming your findings were derived from a single or biased source.

• Learning and improving starts with limitations in research

Dealing with limitations with transparency and integrity helps identify areas for future improvements and developments. It’s a learning process, providing valuable insights into how you can improve methodologies, expand sample sizes, or explore alternate approaches to further support the validity of your findings.

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How To Write Scope and Delimitation of a Research Paper (With Examples)

An effective research paper or thesis has a well-written Scope and Delimitation.  This portion specifies your study’s coverage and boundaries.

Not yet sure about how to write your research’s Scope and Delimitation? Fret not, as we’ll guide you through the entire writing process through this article.

Related: How To Write Significance of the Study (With Examples)

Table of Contents

What is the scope and delimitation of a research paper.

The “Scope and Delimitation” section states the concepts and variables your study covered. It tells readers which things you have included and excluded in your analysis.

This portion tells two things: 1

• The study’s “Scope” – concepts and variables you have explored in your research and;
• The study’s “Delimitation” – the “boundaries” of your study’s scope. It sets apart the things included in your analysis from those excluded.

For example, your scope might be the effectiveness of plant leaves in lowering blood sugar levels. You can “delimit” your study only to the effect of gabi leaves on the blood glucose of Swiss mice.

Where Should I Put the Scope and Delimitation?

This portion is in Chapter 1, usually after the “Background of the Study.”

Why Should I Write the Scope and Delimitation of My Research Paper?

There’s a lot to discover in a research paper or thesis. However, your resources and time dedicated to it are scarce. Thus, given these constraints, you have to narrow down your study. You do this in the Scope and Delimitation.

Suppose you’re studying the correlation between the quantity of organic fertilizer and plant growth . Experimenting with several types of plants is impossible because of several limitations. So, you’ve decided to use one plant type only. 

Informing your readers about this decision is a must. So, you have to state it in your Scope and Delimitation. It also acts as a “disclaimer” that your results are inapplicable to the entire plant kingdom.

What Is the Difference Between Delimitation and Limitation?

People often use the terms “Delimitation” and “Limitation” interchangeably. However, these words differ 2 .

Delimitation refers to factors you set to limit your analysis. It delineates those that are included in your research and those that are excluded. Remember, delimitations are within your control. 

Meanwhile, limitations are factors beyond your control that may affect your research’s results.  You can think of limitations as the “weaknesses” of your study. 

Let’s go back to our previous example. Due to some constraints, you’ve only decided to examine one plant type: dandelions. This is an example of a delimitation since it limits your analysis to dandelions only and not other plant types. Note that the number of plant types used is within your control. 

Meanwhile, your study cannot state that a higher quantity of organic fertilizer is the sole reason for plant growth. That’s because your research’s focus is only on correlation. Since this is already beyond your control, then this is a limitation. 

How To Write Scope and Delimitation: Step-by-Step Guide

To write your research’s Scope and Delimitation section, follow these steps:

1. Review Your Study’s Objectives and Problem Statement

Your study’s coverage relies on its objectives. Thus, you can only write this section if you know what you’re researching. Furthermore, ensure that you understand the problems you ought to answer. 

Once you understand the abovementioned things, you may start writing your study’s Scope and Delimitation.

2. State the Key Information To Explain Your Study’s Coverage and Boundaries

a. The Main Objective of the Research

This refers to the concept that you’re focusing on in your research. Some examples are the following:

• level of awareness or satisfaction of a particular group of people
• correlation between two variables
• effectiveness of a new product
• comparison between two methods/approaches
• lived experiences of several individuals

It’s helpful to consult your study’s Objectives or Statement of the Problem section to determine your research’s primary goal.

b. Independent and Dependent Variables Included

Your study’s independent variable is the variable that you manipulate. Meanwhile, the dependent variable is the variable whose result depends upon the independent variable. Both of these variables must be clear and specific when indicated. 

Suppose you study the relationship between social media usage and students’ language skills. These are the possible variables for the study:

• Independent Variable: Number of hours per day spent on using Facebook
• Dependent Variable: Grade 10 students’ scores in Quarterly Examination in English. 

Note how specific the variables stated above are. For the independent variable, we narrow it down to Facebook only. Since there are many ways to assess “language skills,” we zero in on the students’ English exam scores as our dependent variable. 

c. Subject of the Study

This refers to your study’s respondents or participants. 

In our previous example, the research participants are Grade 10 students. However, there are a lot of Grade 10 students in the Philippines. Thus, we have to select from a specific school only—for instance, Grade 10 students from a national high school in Manila. 

d. Timeframe and Location of the Study

Specify the month(s), quarter(s), or year(s) as the duration of your study. Also, indicate where you will gather the data required for your research. 

e. Brief Description of the Study’s Research Design and Methodology

You may also include whether your research is quantitative or qualitative, the sampling method (cluster, stratified, purposive) applied, and how you conducted the experiment.

Using our previous example, the Grade 10 students can be selected using stratified sampling. Afterward, the researchers may obtain their English quarterly exam scores from their respective teachers. You can add these things to your study’s Scope and Delimitation. 

3. Indicate Which Variables or Factors Are Not Covered by Your Research

Although you’ve already set your study’s coverage and boundaries in Step 2, you may also explicitly mention things you’ve excluded from your research. 

Returning to our previous example, you can state that your assessment will not include the vocabulary and oral aspects of the English proficiency skill. 

Examples of Scope and Delimitation of a Research Paper

1. scope and delimitation examples for quantitative research.

a. Example 1

Research Title

    A Study on the Relationship of the Extent of Facebook Usage on the English Proficiency Level of Grade 10 Students of Matagumpay High School

Scope and Delimitation

(Main Objective)

This study assessed the correlation between the respondents’ duration of Facebook usage and their English proficiency level. 

(Variables used)

The researchers used the number of hours per day of using Facebook and the activities usually performed on the platform to assess the respondents’ extent of Facebook usage. Meanwhile, the respondents’ English proficiency level is limited to their quarterly English exam scores. 

(Subject of the study)

A sample of fifty (50) Grade 10 students of Matagumpay High School served as the study’s respondents. 

(Timeframe and location)

This study was conducted during the Second Semester of the School Year 2018 – 2019 on the premises of Matagumpay High School in Metro Manila. 

(Methodology)

The respondents are selected by performing stratified random sampling to ensure that there will be ten respondents from five Grade 10 classes of the school mentioned above. The researchers administered a 20-item questionnaire to assess the extent of Facebook usage of the selected respondents. Meanwhile, the data for the respondents’ quarterly exam scores were acquired from their English teachers. The collected data are handled with the utmost confidentiality. Spearman’s Rank Order Correlation was applied to quantitatively assess the correlation between the variables.

(Exclusions)

This study didn’t assess other aspects of the respondents’ English proficiency, such as English vocabulary and oral skills. 

Note: The words inside the parentheses in the example above are guides only. They are not included in the actual text.

b. Example 2

  Level of Satisfaction of Grade 11 Students on the Implementation of the Online Learning Setup of Matagumpay High School for SY 2020 – 2021

This study aims to identify students’ satisfaction levels with implementing online learning setups during the height of the COVID-19 pandemic.

Students’ satisfaction was assessed according to teachers’ pedagogy, school policies, and learning materials used in the online learning setup. The respondents included sixty (60) Grade 11 students of Matagumpay High School who were randomly picked. The researchers conducted the study from October 2020 to February 2021. 

Online platforms such as email and social media applications were used to reach the respondents. The researchers administered a 15-item online questionnaire to measure the respondents’ satisfaction levels. Each response was assessed using a Likert Scale to provide a descriptive interpretation of their answers. A weighted mean was applied to determine the respondents’ general satisfaction. 

This study did not cover other factors related to the online learning setup, such as the learning platform used, the schedule of synchronous learning, and channels for information dissemination.

2. Scope and Delimitation Examples for Qualitative Research

  Lived Experiences of Public Utility Vehicle (PUV) Drivers of Antipolo City Amidst the Continuous June 2022 Oil Price Hikes

This research focused on the presentation and discussion of the lived experiences of PUV drivers during the constant oil price hike in June 2022.

The respondents involved are five (5) jeepney drivers from Antipolo City who agreed to be interviewed. The researchers assessed their experiences in terms of the following: (1) daily net income; (2) duration and extent of working; (3) alternative employment opportunity considerations; and (4) mental and emotional status. The respondents were interviewed daily at their stations on June 6 – 10, 2022. 

In-depth one-on-one interviews were used for data collection.  Afterward, the respondents’ first-hand experiences were drafted and annotated with the researchers’ insights. 

The researchers excluded some factors in determining the respondents’ experiences, such as physical and health conditions and current family relationship status. 

 A Study on the Perception of the Residents of Mayamot, Antipolo City on the Political and Socioeconomic Conditions During the Post-EDSA Period (1986 – 1996)

This research aims to discuss the perception of Filipinos regarding the political and socioeconomic economic conditions during the post-EDSA period, specifically during the years 1986 – 1996. 

Ten (10) residents of Mayamot, Antipolo City, who belonged to Generation X (currently 40 – 62 years old), were purposively selected as the study’s respondents. The researchers asked them about their perception of the following aspects during the period mentioned above (1) performance of national and local government; (2) bureaucracy and government services; (3) personal economic and financial status; and (4) wage purchasing power. 

The researchers conducted face-to-face interviews in the respondents’ residences during the second semester of AY 2018 – 2019. The responses were written and corroborated with the literature on the post-EDSA period. 

The following factors were not included in the research analysis: political conflicts and turmoils, the status of the legislative and judicial departments, and other macroeconomic indicators. 

Tips and Warnings

1. use the “5ws and 1h” as your guide in understanding your study’s coverage.

• Why did you write your study?  
• What variables are included?
• Who are your study’s subject
• Where did you conduct the study?
• When did your study start and end?
• How did you conduct the study?

2. Use key phrases when writing your research’s scope

• This study aims to … 
• This study primarily focuses on …
• This study deals with … 
• This study will cover …
• This study will be confined…

3. Use key phrases when writing factors beyond your research’s delimitations

• The researcher(s) decided to exclude …
• This study did not cover….
• This study excluded … 
• These variables/factors were excluded from the study…

4. Don’t forget to ask for help

Your research adviser can assist you in selecting specific concepts and variables suitable to your study. Make sure to consult him/her regularly. 

5. Make it brief

No need to make this section wordy. You’re good to go if you meet the “5Ws and 1Hs”. 

Frequently Asked Questions

1. what are scope and delimitation in tagalog.

In a Filipino research ( pananaliksik ), Scope and Delimitation is called “ Saklaw at Delimitasyon”. 

Here’s an example of Scope and Delimitation in Filipino:

Pamagat ng Pananaliksik

Epekto Ng Paggamit Ng Mga Digital Learning Tools Sa Pag-Aaral Ng Mga Mag-Aaral Ng Mataas Na Paaralan Ng Matagumpay Sa General Mathematics

Sakop at Delimitasyon ng Pag-aaral

Nakatuon ang pananaliksik na ito sa epekto ng paggamit ng mga digital learning aids sa pag-aaral ng mga mag-aaral.

Ang mga digital learning tools na kinonsidera sa pag-aaral na ito ay Google Classroom, Edmodo, Kahoot, at mga piling bidyo mula YouTube. Samantala, ang epekto sa pag-aaral ng mga mag-aaral ng mga nabanggit na digital learning tools ay natukoy sa pamamagitan ng kanilang (1) mga pananaw hinggil sa benepisyo nito sa kanilang pag-aaral sa General Mathematics at (2) kanilang average grade sa asignaturang ito.

Dalawampu’t-limang (25) mag-aaral mula sa Senior High School ng Mataas na Paaralan ng Matagumpay ang pinili para sa pananaliksik na ito. Sila ay na-interbyu at binigyan ng questionnaire noong Enero 2022 sa nasabing paaralan. Sinuri ang resulta ng pananaliksik sa pamamagitan ng mga instrumentong estadistikal na weighted mean at Analysis of Variance (ANOVA). Hindi saklaw ng pananaliksik na ito ang ibang mga aspeto hinggil sa epekto ng online learning aids sa pag-aaral gaya ng lebel ng pag-unawa sa aralin at kakayahang iugnay ito sa araw-araw na buhay. 

2. The Scope and Delimitation should consist of how many paragraphs?

Three or more paragraphs will suffice for your study’s Scope and Delimitation. Here’s our suggestion on what you should write for each paragraph:

Paragraph 1: Introduction (state research objective) Paragraph 2: Coverage and boundaries of the research (you may divide this section into 2-3 paragraphs) Paragraph 3 : Factors excluded from the study

• University of St. La Salle. Unit 3: Lesson 3 Setting the Scope and Limitation of a Qualitative Research [Ebook] (p. 12). Retrieved from https://www.studocu.com/ph/document/university-of-st-la-salle/senior-high-school/final-sg-pr1-11-12-unit-3-lesson-3-setting-the-scope-and-limitation-of-a-qualitative-research/24341582
• Theofanidis, D., & Fountouki, A. (2018). Limitations and Delimitations in the Research Process. Perioperative Nursing (GORNA), 7(3), 155–162. doi: 10.5281/zenodo.2552022

Written by Jewel Kyle Fabula

in Career and Education , Juander How

Jewel Kyle Fabula

Jewel Kyle Fabula is a Bachelor of Science in Economics student at the University of the Philippines Diliman. His passion for learning mathematics developed as he competed in some mathematics competitions during his Junior High School years. He loves cats, playing video games, and listening to music.

Browse all articles written by Jewel Kyle Fabula

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CPS Online Graduate Studies Research Paper (UNH Manchester Library): Limitations of the Study

• Overview of the Research Process for Capstone Projects
• Types of Research Design
• Selecting a Research Problem
• The Title of Your Research Paper
• Before You Begin Writing
• 7 Parts of the Research Paper
• Background Information
• Quanitative and Qualitative Methods
• Qualitative Methods
• Quanitative Methods
• Resources to Help You With the Literature Review
• Non-Textual Elements

Limitations of the Study

• Format of Capstone Research Projects at GSC
• Editing and Proofreading Your Paper
• Acknowledgements
• UNH Scholar's Repository

The limitations of the study are those characteristics of design or methodology that impacted or influenced the interpretation of the findings from your research. They are the constraints on generalizability, applications to practice, and/or utility of findings that are the result of the ways in which you initially chose to design the study and/or the method used to establish internal and external validity.

Price, James H. and Judy Murnan. “Research Limitations and the Necessity of Reporting Them.” American Journal of Health Education 35 (2004): 66-67.

Always acknowledge a study's limitations. It is far better that you identify and acknowledge your study’s limitations than to have them pointed out by your professor and be graded down because you appear to have ignored them.

Keep in mind that acknowledgement of a study's limitations is an opportunity to make suggestions for further research. If you do connect your study's limitations to suggestions for further research, be sure to explain the ways in which these unanswered questions may become more focused because of your study.

Acknowledgement of a study's limitations also provides you with an opportunity to demonstrate that you have thought critically about the research problem, understood the relevant literature published about it, and correctly assessed the methods chosen for studying the problem. A key objective of the research process is not only discovering new knowledge but to also confront assumptions and explore what we don't know.

Claiming limitations is a subjective process because you must evaluate the impact of those limitations . Don't just list key weaknesses and the magnitude of a study's limitations. To do so diminishes the validity of your research because it leaves the reader wondering whether, or in what ways, limitation(s) in your study may have impacted the results and conclusions. Limitations require a critical, overall appraisal and interpretation of their impact. You should answer the question: do these problems with errors, methods, validity, etc. eventually matter and, if so, to what extent?

Price, James H. and Judy Murnan. “Research Limitations and the Necessity of Reporting Them.” American Journal of Health Education 35 (2004): 66-67; Structure: How to Structure the Research Limitations Section of Your Dissertation . Dissertations and Theses: An Online Textbook. Laerd.com.

Descriptions of Possible Limitations

All studies have limitations . However, it is important that you restrict your discussion to limitations related to the research problem under investigation. For example, if a meta-analysis of existing literature is not a stated purpose of your research, it should not be discussed as a limitation. Do not apologize for not addressing issues that you did not promise to investigate in the introduction of your paper.

Here are examples of limitations related to methodology and the research process you may need to describe and to discuss how they possibly impacted your results. Descriptions of limitations should be stated in the past tense because they were discovered after you completed your research.

Possible Methodological Limitations

• Sample size -- the number of the units of analysis you use in your study is dictated by the type of research problem you are investigating. Note that, if your sample size is too small, it will be difficult to find significant relationships from the data, as statistical tests normally require a larger sample size to ensure a representative distribution of the population and to be considered representative of groups of people to whom results will be generalized or transferred. Note that sample size is less relevant in qualitative research.
• Lack of available and/or reliable data -- a lack of data or of reliable data will likely require you to limit the scope of your analysis, the size of your sample, or it can be a significant obstacle in finding a trend and a meaningful relationship. You need to not only describe these limitations but to offer reasons why you believe data is missing or is unreliable. However, don’t just throw up your hands in frustration; use this as an opportunity to describe the need for future research.
• Lack of prior research studies on the topic -- citing prior research studies forms the basis of your literature review and helps lay a foundation for understanding the research problem you are investigating. Depending on the currency or scope of your research topic, there may be little, if any, prior research on your topic. Before assuming this to be true, though, consult with a librarian. In cases when a librarian has confirmed that there is no prior research, you may be required to develop an entirely new research typology [for example, using an exploratory rather than an explanatory research design]. Note again that discovering a limitation can serve as an important opportunity to identify new gaps in the literature and to describe the need for further research.
• Measure used to collect the data -- sometimes it is the case that, after completing your interpretation of the findings, you discover that the way in which you gathered data inhibited your ability to conduct a thorough analysis of the results. For example, you regret not including a specific question in a survey that, in retrospect, could have helped address a particular issue that emerged later in the study. Acknowledge the deficiency by stating a need for future researchers to revise the specific method for gathering data.
• Self-reported data -- whether you are relying on pre-existing data or you are conducting a qualitative research study and gathering the data yourself, self-reported data is limited by the fact that it rarely can be independently verified. In other words, you have to take what people say, whether in interviews, focus groups, or on questionnaires, at face value. However, self-reported data can contain several potential sources of bias that you should be alert to and note as limitations. These biases become apparent if they are incongruent with data from other sources. These are: (1) selective memory [remembering or not remembering experiences or events that occurred at some point in the past]; (2) telescoping [recalling events that occurred at one time as if they occurred at another time]; (3) attribution [the act of attributing positive events and outcomes to one's own agency but attributing negative events and outcomes to external forces]; and, (4) exaggeration [the act of representing outcomes or embellishing events as more significant than is actually suggested from other data].

Possible Limitations of the Researcher

• Access -- if your study depends on having access to people, organizations, or documents and, for whatever reason, access is denied or limited in some way, the reasons for this need to be described.
• Longitudinal effects -- unlike your professor, who can literally devote years [even a lifetime] to studying a single topic, the time available to investigate a research problem and to measure change or stability over time is pretty much constrained by the due date of your assignment. Be sure to choose a research problem that does not require an excessive amount of time to complete the literature review, apply the methodology, and gather and interpret the results. If you're unsure whether you can complete your research within the confines of the assignment's due date, talk to your professor.
• Cultural and other type of bias -- we all have biases, whether we are conscience of them or not. Bias is when a person, place, or thing is viewed or shown in a consistently inaccurate way. Bias is usually negative, though one can have a positive bias as well, especially if that bias reflects your reliance on research that only support for your hypothesis. When proof-reading your paper, be especially critical in reviewing how you have stated a problem, selected the data to be studied, what may have been omitted, the manner in which you have ordered events, people, or places, how you have chosen to represent a person, place, or thing, to name a phenomenon, or to use possible words with a positive or negative connotation.

NOTE:   If you detect bias in prior research, it must be acknowledged and you should explain what measures were taken to avoid perpetuating that bias.

• Fluency in a language -- if your research focuses on measuring the perceived value of after-school tutoring among Mexican-American ESL [English as a Second Language] students, for example, and you are not fluent in Spanish, you are limited in being able to read and interpret Spanish language research studies on the topic. This deficiency should be acknowledged.

Aguinis, Hermam and Jeffrey R. Edwards. “Methodological Wishes for the Next Decade and How to Make Wishes Come True.” Journal of Management Studies 51 (January 2014): 143-174; Brutus, Stéphane et al. "Self-Reported Limitations and Future Directions in Scholarly Reports: Analysis and Recommendations." Journal of Management 39 (January 2013): 48-75; Senunyeme, Emmanuel K. Business Research Methods . Powerpoint Presentation. Regent University of Science and Technology; ter Riet, Gerben et al. “All That Glitters Isn't Gold: A Survey on Acknowledgment of Limitations in Biomedical Studies.” PLOS One 8 (November 2013): 1-6.

Structure and Writing Style

Information about the limitations of your study are generally placed either at the beginning of the discussion section of your paper so the reader knows and understands the limitations before reading the rest of your analysis of the findings, or, the limitations are outlined at the conclusion of the discussion section as an acknowledgement of the need for further study. Statements about a study's limitations should not be buried in the body [middle] of the discussion section unless a limitation is specific to something covered in that part of the paper. If this is the case, though, the limitation should be reiterated at the conclusion of the section. If you determine that your study is seriously flawed due to important limitations, such as, an inability to acquire critical data, consider reframing it as an exploratory study intended to lay the groundwork for a more complete research study in the future. Be sure, though, to specifically explain the ways that these flaws can be successfully overcome in a new study. But, do not use this as an excuse for not developing a thorough research paper! Review the tab in this guide for developing a research topic. If serious limitations exist, it generally indicates a likelihood that your research problem is too narrowly defined or that the issue or event under study is too recent and, thus, very little research has been written about it. If serious limitations do emerge, consult with your professor about possible ways to overcome them or how to revise your study. When discussing the limitations of your research, be sure to: Describe each limitation in detailed but concise terms; Explain why each limitation exists; Provide the reasons why each limitation could not be overcome using the method(s) chosen to acquire or gather the data [cite to other studies that had similar problems when possible]; Assess the impact of each limitation in relation to the overall findings and conclusions of your study; and, If appropriate, describe how these limitations could point to the need for further research. Remember that the method you chose may be the source of a significant limitation that has emerged during your interpretation of the results [for example, you didn't interview a group of people that you later wish you had]. If this is the case, don't panic. Acknowledge it, and explain how applying a different or more robust methodology might address the research problem more effectively in a future study. A underlying goal of scholarly research is not only to show what works, but to demonstrate what doesn't work or what needs further clarification. Aguinis, Hermam and Jeffrey R. Edwards. “Methodological Wishes for the Next Decade and How to Make Wishes Come True.” Journal of Management Studies 51 (January 2014): 143-174; Brutus, Stéphane et al. "Self-Reported Limitations and Future Directions in Scholarly Reports: Analysis and Recommendations." Journal of Management 39 (January 2013): 48-75; Ioannidis, John P.A. "Limitations are not Properly Acknowledged in the Scientific Literature." Journal of Clinical Epidemiology 60 (2007): 324-329; Pasek, Josh. Writing the Empirical Social Science Research Paper: A Guide for the Perplexed. January 24, 2012. Academia.edu; Structure: How to Structure the Research Limitations Section of Your Dissertation. Dissertations and Theses: An Online Textbook. Laerd.com; What Is an Academic Paper? Institute for Writing Rhetoric. Dartmouth College; Writing the Experimental Report: Methods, Results, and Discussion. The Writing Lab and The OWL. Purdue University.

Information about the limitations of your study are generally placed either at the beginning of the discussion section of your paper so the reader knows and understands the limitations before reading the rest of your analysis of the findings, or, the limitations are outlined at the conclusion of the discussion section as an acknowledgement of the need for further study. Statements about a study's limitations should not be buried in the body [middle] of the discussion section unless a limitation is specific to something covered in that part of the paper. If this is the case, though, the limitation should be reiterated at the conclusion of the section.

If you determine that your study is seriously flawed due to important limitations , such as, an inability to acquire critical data, consider reframing it as an exploratory study intended to lay the groundwork for a more complete research study in the future. Be sure, though, to specifically explain the ways that these flaws can be successfully overcome in a new study.

But, do not use this as an excuse for not developing a thorough research paper! Review the tab in this guide for developing a research topic . If serious limitations exist, it generally indicates a likelihood that your research problem is too narrowly defined or that the issue or event under study is too recent and, thus, very little research has been written about it. If serious limitations do emerge, consult with your professor about possible ways to overcome them or how to revise your study.

When discussing the limitations of your research, be sure to:

• Describe each limitation in detailed but concise terms;
• Explain why each limitation exists;
• Provide the reasons why each limitation could not be overcome using the method(s) chosen to acquire or gather the data [cite to other studies that had similar problems when possible];
• Assess the impact of each limitation in relation to the overall findings and conclusions of your study; and,
• If appropriate, describe how these limitations could point to the need for further research.

Remember that the method you chose may be the source of a significant limitation that has emerged during your interpretation of the results [for example, you didn't interview a group of people that you later wish you had]. If this is the case, don't panic. Acknowledge it, and explain how applying a different or more robust methodology might address the research problem more effectively in a future study. A underlying goal of scholarly research is not only to show what works, but to demonstrate what doesn't work or what needs further clarification.

Aguinis, Hermam and Jeffrey R. Edwards. “Methodological Wishes for the Next Decade and How to Make Wishes Come True.” Journal of Management Studies 51 (January 2014): 143-174; Brutus, Stéphane et al. "Self-Reported Limitations and Future Directions in Scholarly Reports: Analysis and Recommendations." Journal of Management 39 (January 2013): 48-75; Ioannidis, John P.A. "Limitations are not Properly Acknowledged in the Scientific Literature." Journal of Clinical Epidemiology 60 (2007): 324-329; Pasek, Josh. Writing the Empirical Social Science Research Paper: A Guide for the Perplexed . January 24, 2012. Academia.edu; Structure: How to Structure the Research Limitations Section of Your Dissertation . Dissertations and Theses: An Online Textbook. Laerd.com; What Is an Academic Paper? Institute for Writing Rhetoric. Dartmouth College; Writing the Experimental Report: Methods, Results, and Discussion . The Writing Lab and The OWL. Purdue University.

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ORIGINAL RESEARCH article

Anxiety mediates association between sex and jaw function limitation in temporomandibular disorder patients from china.

• 1 State Key Laboratory of Oral Disease, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
• 2 West China Hospital of Sichuan University, Chengdu, China
• 3 Department of Nursing, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
• 4 Department of Orthodontics, College and Hospital of Stomatology, Guangxi Medical University, Nanning, China

Aim: The objective of this study is to explore the relationship between sex and jaw function and to test whether anxiety mediates the causal relationship between sex and jaw function in temporomandibular disorders (TMDs) patients.

Methods: A total of 488 participants with TMD were included in the analysis. Demographic data were collected. Generalized anxiety symptoms and anxiety severity were initially assessed using the GAD-7 questionnaire. And jaw function limitation was measured using the JFLS-8 scale. A directed acyclic graph (DAG) was used in this study to evaluate the hypotheses. Mediation analysis was conducted to explore causality and to calculate the total effect, natural direct effect (NDE) and natural indirect effect (NIE).

Results: In TMD patients, there was a significant association between female and jaw function ( r  = 0.17, p  < 0.001), female and anxiety ( r  = 0.15, p  = 0.002), anxiety and jaw function ( r  = 0.35, p  < 0.001). In addition, sex can directly lead to differences in impaired jaw function (NDE: 3.719, 95% CI: 1.619–5.828, p  < 0.001), and can also be causally related to jaw function through anxiety (NIE: 1.146, 95% CI: 0.267–2.024, p  = 0.011). And the total effect was 4.865 (95% CI, 2.709–7.029, p  < 0.001).

Conclusion: A causal mechanism was found that anxiety acts as a mediator of sex effects on jaw function. Therefore, psychological factors need to be taken into account in the treatment of female TMD patients. Further clinical trials are needed to explore whether psychotherapy is more beneficial to improve jaw function in female TMD patients.

1 Introduction

Temporomandibular disorder (TMD) is an umbrella term for a group of disorders, including musculoskeletal and neuromuscular disorders, that share the same or similar pathogenetic factors and clinical symptoms. TMD can affect the temporomandibular joint (TMJ), the masticatory muscles and their associated structures ( 1 ). Although TMD is generally self-limiting ( 2 , 3 ), it can have a serious impact on quality of life, jeopardizing the normal functioning of the oral and maxillofacial system, including clinical symptoms such as orofacial pain, stiffness, limited voice and jaw movements ( 4 , 5 ). TMD is also associated with different types of primary headache disorders and chronic daily headache ( 6 , 7 ), and affecting the patient’s facial aesthetics, as well as their physical and psychological health ( 8 – 11 ). When TMJ disorders and primary headache disorders co-exist in comorbidity, diagnosis and treatment become a challenge ( 7 ).

Epidemiologic studies have shown that about 50–75% of the population is affected to some degree and shows some signs of TMD. Traditionally, TMD has been thought to affect mainly females of childbearing age ( 12 ). There is evidence that the prevalence is approximately two times higher in females than in males ( 13 ), and is most common in the second through fourth decade of reproductive life ( 14 ). TMD is often thought to be multifactorial, including psychosocial factors. However, the reasons for the higher prevalence of TMD in females than in males remain unclear. Recent research suggests that a combination of genes, psychological and perception of pain may play a role in the onset of TMD as well as its prolonged duration ( 15 , 16 ).

TMD is considered to be related to psychosomatic factors such as anxiety, stress, and sleep disorders ( 17 , 18 ). Among them anxiety disorders are the most common of all mental disorders. In 2019, 301 million people worldwide suffer from anxiety disorders, with more females than males suffering from them ( 19 ). Affective distress (in form of anxiety) and anxiety sensitivity have been associated with pain in experimental and clinical-based investigations. A bidirectional relationship between TMD and anxiety is thought to exist and multiple psychological variables can serve as predictors of TMD ( 20 ). Several studies have pointed to a higher prevalence of anxiety in patients with TMD compared to healthy individuals ( 16 , 21 , 22 ). And psychosocial disorders play an important role in the development of TMD ( 11 , 23 ).

Most of the current studies have focused on sex differences in the incidence of TMD and pain levels in patients with TMD, while fewer studies have examined whether there are differences in life-affecting jaw function limitations among patients with TMD. The specific association between TMD and anxiety has been the subject of several studies, and there have been a number of studies that have explored the mechanisms behind this through functional MRI ( 24 ). At the same time, sex differences in TMD have been consistently observed, but few studies have considered that anxiety may play an effect in the middle of this. To our knowledge, there are currently no studies that have considered anxiety as a mediator to conduct causal analysis between sex and the causal relationship of TMD.

Because of the difficulty of objectively measuring pain and function, the use of patient-reported outcomes (PROs) in dentistry is essential for the evaluation and diagnosis of TMJ disorders and headaches ( 25 , 26 ). The Jaw Functional Limitations Scale (JFLS) is the International Network for Orofacial Pain and Related Disorders Methodology’s recommended PROM for the evaluation of jaw-related disabilities ( 25 ). JFLS is a self-administered questionnaire developed in 2008 that exhibits improved psychometric characteristics and has good validity in TMD patients ( 27 ). Compared to the JFLS-20, the JFLS-8 is shorter while demonstrating excellent content validity, construct validity, internal consistency ( α  = 0.82, only TMD patients), and reliability (CCC rho = 0.81) of the JFLS-8 questionnaire ( 27 , 28 ). Therefore, in this study JFLS-8 was chosen to measure jaw function limitation.

The present study initiated with the aim of exploring the relationship between sex and jaw function and testing the hypotheses that anxiety mediates the causal relationship between sex and jaw function.

2 Materials and methods

2.1 participants.

This observational cross-sectional study was performed at the Department of Temporomandibular Joint, West China Hospital of Stomatology, Sichuan University, from February 2022 to October 2022. This study was approved by the Ethics Committee of West China Hospital of Stomatology of Sichuan University (WCHSIRB-D-2022-137) and in compliance with the Declaration of Helsinki. The inclusion criteria for this study were: (a) consent to participate in this study, (b) the data of patients was complete and sufficient and (c) diagnosed with TMD by a TMD specialist based on DC/TMD protocols. Exclusion criteria were (a) children/adolescents aged below 18, (b) cognitive impairment or illiteracy and (c) no history of facial surgery or non-operative facial injuries. According to the sample size estimate, a minimum of 119 participants was required for this study at Cohen’s f 2  = 0.15 (medium effect size), α  = 0.05, and power = 0.95.

2.2 Measurements

Data included demographics, Generalized Anxiety Disorder 7-item (GAD-7) and Jaw Functional Limitation Scale, 8-item version (JFLS-8). Demographics included age, sex, education level and income of the participants. The age of the participants was recorded as a continuous variable in years, and the sex variable was recorded on the basis of the sex registered in the ID card ( 29 ). Education levels were categorized into three groups: (1) elementary/junior high/senior high school degree, (2) college/bachelor’s degree, and (3) master’s/doctor’s degree. We categorized the per capita household income of the participants into three categories: (1) less than 3,000 RMB per month; (2) 3,000–6,000 RMB per month; and (3) more than 6,000 RMB per month.

The GAD-7 questionnaire was used to initially assess generalized anxiety symptoms and the severity of anxiety. The respondents were supposed to select a description that matches their behavior and feelings over the past 2 weeks on a scale ranging from 0 (not at all) to 3 (nearly every day). As recommended by the latest Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) ( 30 ) diagnostic criteria, the JFLS was used to measure function limitation in patients with TMD ( 30 , 31 ). The jaw function limitation in this study was measured with the 8-item version. This 8-item instrument were developed as a global measure of functional limitation with each item scoring from 0 (no limitation) to 10 (severe limitation) for different levels of limitation in jaw activities including chewing, smiling, swallowing, etc.

2.3 Statistical analysis

A directed acyclic graph (DAG) was used in this study to evaluate the hypotheses of the study based on a priori knowledge ( Figure 1 ). The primary endpoint (dependent variable) was the JFLS-8 score. Sex was considered as an independent variable according to previous studies 122 because of their potential impact on mandibular functional limitations. The remaining demographic characteristics (age, education, income) were analyzed as covariates due to their no effect on sex but on the measured outcome (JFLS-8 score).

Figure 1 . The hypothesized relationships between variables and jaw function demonstrating by directed acyclic graph (DAG). The yellow box indicates exposure. The green box indicates mediator. The blue box indicates outcome, and the gray boxes indicate confounders. The yellow path indicates the direct effect and the green paths indicate the indirect effects.

The Shapiro–Wilk test was employed to test the normality of the variables. The differences between categorical variables were compared using the chi-square test and ordinal variables using the Mann–Whitney U test. To initially explore the relationship between the variables, the Spearman correlation coefficients were calculated and adjusted by the Benjamin-Hochberg method.

Causal mediation analysis is conducted to explore causal relationships and obtain direct and indirect effect values. This analysis decomposed the total effect of exposure into estimates of natural direct and indirect effects. Indirect effects are the effects through mediators in the total effect of exposure on the outcome, whereas direct effects reflect the remainder of the total effect. The 95% confidence intervals (CI) of the estimates were calculated using the Bootstrap method (5,000 stimulations).

Analyses were performed using R version 4.3.1 (R Foundation) with a p  < 0.05 indicating significance. The regression model was generated by the R package ‘modelsummary’ (version 1.2.0). The mediation analysis was conducted through R package “medflex” (version 0.6–10). The R package “likert” (version 1.3.5) was used for likert plot to visualize the results of likert scales including GAD-7 scale and JFLS-8 scale. The workflow is depicted in Figure 2 . Above analyses were used and interpreted in compliance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) checklist.

Figure 2 . Overview of study design and workflow. GAD-7, Generalized Anxiety Disorder 7-item; JFLS-8, Jaw Functional Limitation Scale, 8-item version.

3.1 Baseline characteristics of the study population

Of the 601 individuals who completed the questionnaire, 73 participants younger than 18 years old and 40 individuals without TMD based on the definition of DC/TMD were excluded. A final total of 488 were included in the following analyses, with 99 males and 389 females ( Table 1 ), most of whom were from southwest China. All variables were non-normally distributed ( p  < 0.05). Of the whole study population, the median age was 27 years, and the median JFLS-8 and GAD-7 scores were 13 and 4, respectively. Compared to the median score of 9.5 in the male group, the female group had a significantly higher JFLS-8 score (median 14.0, p  < 0.001). Similarly, the median GAD-7 score was significantly higher among females (median 4.0, p  = 0.001) than among males (median 2.0). In addition, the income of the two groups showed a significant difference ( p  = 0.020), while there was no significant difference in age ( p  = 0.134) and education level ( p  = 0.467) between the male and female participants. Based on the sample size included in this study, the effect size was calculated to be 0.035 at α  = 0.05 and power = 0.95.

Table 1 . Baseline characteristics of the study population.

The JFLS-8 scale and GAD-7 scale used were in good consistency, and their reliability as assessed by the Cronbach’s alpha coefficient was 0.800 (95% CI: 0.773–0.826) and 0.932 (95% CI: 0.922–0.941) respectively. The responses of JFLS-8 and GAD-7 were visualized in Figures 3 , 4 . The results showed that the median scores on chewing tough food (males: 3.0, females: 4.0, p  < 0.001) and chewing chicken (males: 2.0, females: 5.0, p  < 0.001) were significantly higher in females than in males. Similar results were observed in the median scores of opening wide enough to drink from a cup (males: 0.0, females: 0.0, p  = 0.015), yawning (males: 2.0, females: 3.0, p  = 0.047) and talking (males: 0.0, females: 0.0, p  = 0.050). As for the GAD-7 scale, the median scores were significantly higher in females than in males on all items except item 5.

Figure 3 . Distribution of JFLS-8 scale responses. The likert plot was used to graphically represent the mean values of each item scores of JFLS-8 among males and females. P -values were calculated by the Mann–Whitney U test. The number after the JFLS indicates the item number in the JFLS questionnaire. JFLS, Jaw Functional Limitation Scale. * p  < 0.05; ** p  < 0.01; *** p  < 0.001.

Figure 4 . Distribution of GAD-7 scale responses. Likert plot was used to graphically represent the participants’ response to each item of the GAD-7 questionnaire stratified by sex. P -values were calculated by the Mann–Whitney U test. The number after the GAD indicates the item number in the GAD questionnaire. GAD, Generalized Anxiety Disorder. * p  < 0.05; ** p  < 0.01; *** p  < 0.001.

3.2 Correlation between variables

Spearman’s correlation coefficients adjusted with the Benjamini-Hochberg method are shown in Table 2 . It revealed that JFLS-8 scores were significantly and positively correlated with female gender ( r  = 0.17, p  < 0.001) and GAD-7 scores ( r  = 0.35, p  < 0.001), where female in turn was significantly and positively correlated with GAD-7 scores ( r  = 0.15, p  = 0.002). Additionally, significant negatively correlations were also observed between JFLS-8 scores and income ( r  = −0.17, p  < 0.001). Meanwhile, female is negatively correlated with income ( r  = −0.10, p  = 0.051), and although it does not achieve significant level, the p value is very close to 0.05.

Table 2 . Spearman correlation coefficient matrix.

Table 3 . Multiple regression models for the association between variables and jaw function.

3.3 Multiple regression models

Multiple regression models ( Table 3 ) showed that JFLS-8 score was significantly positively associated with GAD-7 score (0.761, 95% CI: 0.552–0.969, p  < 0.001) after adjustment for age, sex, education and income. In addition, JFLS-8 score was also significantly positively associated with age (0.100, 95% CI: 0.001–0.199, p  = 0.048) and female (3.726, 95% CI: 1.292–6.161, p  = 0.003), while JFLS-8 score was negatively associated with income (−1.710, 95% CI: −3.154 – −0.266, p  = 0.020). After adjustment for age, sex and education (without including income), JFLS-8 score was significantly positively associated with age (0.106, 95% CI: 0.006–0.205, p  = 0.037), female (4.025, 95% CI: 1.592–6.457, p  = 0.001) and GAD-7 score (0.780, 95% CI: 0.572–0.988, p  < 0.001).

3.4 The mediating relationship of GAD-7 scores between sex and JFLS-8 scores

On the basis of the DAG, sex and GAD-7 scores were selected to explore whether sex had a causal effect on JFLS-8 and whether GAD-7 had a mediating effect therein. Mediation analysis showed that sex had a significant causal effect on both jaw function and anxiety ( Figure 5 ). Meanwhile, anxiety played a mediator role in the pathway of female was more likely to lead to jaw function limitation. The total effect of sex on JFLS-8 scores was 4.865 (NDE: 95% CI: 2.709–7.029, p  < 0.001). GAD-7 scores mediated 22% of the total causal effect (NIE: 1.074, 95% CI: 0.267–2.024, p  = 0.011). After adjusting for the mediating effect of GAD-7 scores, the direct effect (sex on JFLS-8 scores not due to GAD-7 scores) was 3.719 (95% CI: 1.619–5.828, p  < 0.001).

Figure 5 . Mediation analysis results of sex predicting JFLS-8 mediated by GAD-7. (A) Forest plot of mediation analysis results. (B) Causal directed acyclic graph of mediation analysis results shows the mediation analysis of GAD-7 scores (anxiety) on the relationship between sex and JFLS-8 (jaw function). The yellow path indicates the direct effect and the green paths indicate the indirect effects. Estimates and CIs calculated using 5,000 bootstraps. All models adjusting for age, education and income. Values are displayed as β (95%CI). CI, confidence interval; NDE, natural direct effect; NIE, natural indirect effect; TE, total effect. * p  < 0.05; ** p  < 0.01; *** p  < 0.001.

4 Discussion

In the present study, we found that in TMD patients there was a significant causally association between female and jaw function, female and anxiety, anxiety and jaw function. Moreover, a causal mechanism was observed that sex can directly affects jaw function, and can also limit jaw function by causing anxiety.

Our study reports a predominance of females among TMD patients, which is consistent with previous studies ( 12 , 32 ). A recent systematic review and meta-analysis ( 13 ) found that females are twice as likely as males to develop TMD. Sex has long been medically defined as a biological trait, and the primary sex determination in humans occurs at fertilization and is dependent on the two sex chromosomes of the fertilized egg ( 33 ). Interventions to change a person’s external sex characteristics, including the use of sex hormones and other medications, do not change a person’s genetic code and cannot alter biological sex ( 34 ). Therefore, sex can be considered one of the causes of TMD based solely on its correlation with TMD without the need for a causal analysis. Although it is not entirely clear what aspects of biology, psychology, or social roles are responsible for females being more likely to suffer from TMD than males, various explanations have been put forward ( 35 ). There is the notion that females are more willing to report pain ( 36 , 37 ) and attend clinics than males, and that the mechanism behind this may be related to sex differences in pain thresholds and tolerance times due to ovarian hormones ( 38 – 40 ).

The results showed the total and direct effects of sex on jaw function and the mediating effect of anxiety were significant. Our study confirms a causal mechanism of sex differences in jaw function limitation that sex induces differences in the anxiety level, and consequently impacts jaw function. There is a bidirectional relationship between anxiety disorders and TMD ( 41 , 42 ). The prevalence of anxiety is higher in patients with TMD ( 21 , 22 ). Some studies have speculated that the prevalence of TMD may be associated with the fact that women are under greater stress in society ( 43 , 44 ). Anxiety has been shown to affect muscle activity ( 45 , 46 ) and may also affect changes in the bones of TMJ ( 46 , 47 ). Anxiety may affect metabolism and blood flow by altering sympathetic nervous system ( 48 , 49 ), e.g., reduced muscle blood perfusion; reduced proprioceptive inputs, etc. directly affecting the performance of the masticatory muscles, thereby reducing the efficiency of complex movements such as chewing, leading to increased fatigue and ultimately reduced jaw function.

The mechanism underlying this may be related to anterior cingulate cortex and anterior insula. They are two important regions responsible for encoding the emotional and motivational aspects of pain. They have been studied by functional and structural magnetic resonance imaging (MRI) methods and are currently thought to be associated with orofacial pain ( 50 ). A joint analysis of mastication and orofacial pain studies showed joint activation of the left insula, left primary motor cortex, and right primary somatosensory cortex ( 51 , 52 ). In a longitudinal treatment study, activation in the right anterior insula and right cerebellum was reduced in patients with TMD during treatment ( 53 ). And anxiety-related TMD symptoms may be associated with the anterior insula. It has been shown that a reduction in anxiety in TMD patients during splinting is associated with a reduction in functional magnetic resonance imaging activation in the left anterior insula and right posterior insula ( 24 ). This may be related to the fact that the anterior insula is interconnected with the limbic system (amygdala, anterior prefrontal, and cingulate cortex) thus the anterior insula acts as an important pivot between the internal emotional state and somatosensory inputs to somatosensory cell labeling ( 54 ).

A large number of patients with TMD are suffering from a sex-differentiated decrease in life satisfaction ( 11 ). Psychological factors need to be taken into account in the treatment of female TMD patients due to the result that 22% of the total effect of sex on the development of TMD was mediated by anxiety. This could mean that the assessment and interventions of anxiety are considered to have an impact on the improvement of jaw function limitation. Previous studies have revealed that both psychological and oral interventions are beneficial in the relief of anxiety or TMD symptoms ( 24 , 55 , 56 ). Patients with TMD improved significantly when provided with treatments to get anxiety under control, including medication ( 57 , 58 ), stress management ( 59 ), and biofeedback ( 60 , 61 ). Our study suggested that treatment for anxiety may be more beneficial in improving jaw function in female TMD patients compared to male patients and future clinical trials are needed to explore whether psychotherapy is more effective for female TMD patients and to elucidate the biological mechanisms involved.

A number of considerations should be taken into account when interpreting the results. The main limitation is that the severity of anxiety and jaw function limitation was assessed by patients completing a self-assessment questionnaire without a professional diagnosis by a relevant medical professional. This may lead to a less accurate diagnosis and assessment. Secondly, the demographic information is incompletely considered at the time of collection. Estimates of direct and indirect effects will be affected if there is an uncontrolled common cause of the mediator and the outcome affected by the exposure. However, the major factors associated with exposure and outcome have been taken into account. Third, the questionnaire collected in this study was for anxiety but not for stress, which may also be mediators of sex-induced jaw function limitation. Similarly, income may also be a mediator. Thus, future studies could analyze the causal effect between them and sex and jaw function. Moreover, we recruited our sample from West China Hospital of Stomatology, thus limiting the generalizability of our findings to local TMD patients since it was only conducted at one study center, and whether the results can be extended to the whole population needs to be further investigated.

5 Conclusion

There were significant sex differences in jaw function limitation and the causal mediation analysis revealed that anxiety mediated the effect of sex on mandibular functional limitation in TMD patients. The findings suggest that actions to promote gender equality are needed to ensure equitable population health. Further clinical are needed to determine whether interventions to relieve anxiety may be more effective in improving female TMD patients’ symptoms.

Data availability statement

The data supporting the findings of this study will be made available by the corresponding author upon reasonable request.

Ethics statement

The studies involving humans were approved by Ethics Committee of West China Hospital of Stomatology of Sichuan University. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.

Author contributions

LC: Methodology, Software, Validation, Visualization, Writing – original draft. SZ: Data curation, Validation, Writing – original draft. YT: Investigation, Visualization, Writing – original draft. YZ: Formal analysis, Methodology, Visualization, Writing – original draft. SF: Formal analysis, Methodology, Validation, Writing – original draft. YY: Validation, Writing – original draft. XX: Conceptualization, Funding acquisition, Project administration, Resources, Supervision, Writing – review & editing.

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This work was supported by the Technology Innovation Project of Science and Technology Bureau of Chengdu (2022-YF05-01691-SN), Clinical Research Project (LCYJ-2023-YY-2) and Research and Develop Program (RCDWJS2023-13) of West China Hospital of Stomatology, Sichuan University, and Sichuan Science and Technology Program (No. 2023JDRC0096).

Acknowledgments

We thank all the participants in the study. We also acknowledge the reviewers and editors for viewing our work.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher's note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

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Keywords: anxiety, sex, jaw function, temporomandibular disorders, mediation analysis, gender equity

Citation: Chen L, Zhang S, Tan Y, Zheng Y, Fang S, Yi Y and Xiong X (2024) Anxiety mediates association between sex and jaw function limitation in temporomandibular disorder patients from China. Front. Neurol . 15:1398788. doi: 10.3389/fneur.2024.1398788

Received: 11 March 2024; Accepted: 24 April 2024; Published: 13 May 2024.

Reviewed by:

Copyright © 2024 Chen, Zhang, Tan, Zheng, Fang, Yi and Xiong. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) . The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Xin Xiong, [email protected]

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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