Through working with doctoral students, I have realized that it is often difficult for them to articulate their “dissertation limitations” or the limitations to a study. Quickly before we move on, let’s answer the question, what are research limitations? The study’s limitations are its flaws. Often, they are the result of the unavailability of resources, small sample size, flawed methodology, etc. Some fear that research study limitations may point out weaknesses that give their advisors “ammunition” against them or that they will say something that discredits their own research. Others are very proud of their work and genuinely feel that they have completed a great study. In the end, however, all studies have limitations.

If you go into a doctoral defense and tell your committee that you have no limitations in your research, they will likely feel that you have not grown as a researcher and do not fully understand the research process. However, not everything in this process is in our control, and this is ultimately the source of limitations. For this reason, it is important to think through these limitations, to present them in your dissertation, and to be prepared to discuss them and the impact they have had on your findings and conclusions.

Think of dissertation limitations or research limitations as the “what could have been better?” To say you have no limitations is to say that nothing could have been better. Most often, there are a lot of aspects of your research that could be improved. After all, this is a learning process. Therefore, prioritize the limitations that had the most significant impact on the quality of your study and your ability to address your guiding research questions. Price and Murnan (2004) defined limitations as:

“The dissertation 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 or the method used to establish internal and external validity or the result of unanticipated challenges that emerged during the study.”

1. Identify Your Dissertation Limitations and How to Write Limitations in Research.

There are often dissertation limitations that can be identified before your study and limitations you can only identify after the study has been completed.  Some limitations are inherent to the decisions you are making; these can be predicted or outlined in Chapter 1 (following a five-chapter format).  Other limitations can only be known after you have collected and analyzed your data and these are often addressed in Chapter 5.

Both are a critical appraisal of your own research. There is, however, a delicate balance between critically appraising your study and undermining your own validity and reliability.  For this reason, it is important to think through not just the limitations, but also the impact they have had.

2. Reflect on Your Dissertation Limitations.

Therefore, you will not only want to identify your dissertation limitations but also reflect on them.  What were the choices made that led to these limitations?  Could they have been avoided by choosing alternative options?  How did they impact your results? Ultimately, you are also beating your committee to the punch by thinking through these questions and addressing them in the limitations section of your dissertation.

Be careful, however, to keep your limitations within the scope of what you are actually doing.  This means your study cannot be limited by not addressing issues that were not part of what you proposed to address. It also means that negative results or not finding what you expected to find is not a limitation.  Unexpected findings do warrant future research, but your results are your results.  They are not a limitation; only how you got to these results and how they can be interpreted can be limitations. Common limitations include:

1. Data issues, such as the lack of available data; lack of reliable data; self-reported data (i.e., selective memory, attribution); access to data; bias (i.e, hindsight bias, pro-social bias); language, fluency, and literacy; measurement errors; and sample size
2. Time issues, such as longitudinal effects
3. Extant literature issues, such as limited previous research on your topic[1]

3. Inform Future Research.

Another important question is: Could you make recommendations for overcoming these issues in future studies?  In this sense, your limitations section provides an opportunity for learning from your mistakes and making recommendations for future research that accounts for these mistakes.  For example, if you think your sample size could have been better, make a recommendation that the study is reconducted with a larger sample size.  If you think the results cannot be transferred beyond the sample, this would be the limitations, but you would have to identify the source of this limitation.

If the source is your sampling technique, then the recommendation for future research may be to use a different sampling approach.  However, if your limitation comes from the study of a unique population, then you might recommend a different target population.

Addressing the considerations discussed in this blog will ultimately provide you with the opportunity to show you have grown as a researcher.  This takes humility. As the purpose of a dissertation is to contribute new knowledge in your field and to demonstrate that you can do so as an independent scholar, the limitations section allows you to demonstrate this.

It shows you understand the research process, that you know what you have contributed and how it can be improved, and that you can critically assess your own knowledge. It also keeps you “in check” and prevents you from overstating the importance of what you have contributed.  You are not expected to hide your flaws—you are expected to know them and present them to the reader with humility.  

Reference

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

[1] A word of caution of claiming there is limited research on your topic-  be sure this is the case before you claim this is the case.  When I hear this claim from my students, I will automatically question it.  Be sure you have assessed your topic using different keywords, using broader keywords, and looking at current literature.  If you feel that a limitation of your study is that there is limited extant literature on your topic, be prepared to discuss why and also to discuss the closest studies that do exist on the topic.