Supervisors will often suggest (or straight-up tell you) that your dissertation topic is too broad. It's no surprise. Coming up with a broad dissertation topic is such an easy thing to do, especially if you are an undergraduate student (i.e., it is your first dissertation). However, seldom will your supervisor explain why it is too broad or help you understand how to identify whether your dissertation topic is too broad in the first place. Since this is a tricky thing to do, we can't claim that this article will have all the answers, especially since there are so many reasons why different dissertation topics may be too broad. But it should help you to identify (a) some of the factors that make a dissertation topic too broad and (b) how to try and identifying whether your dissertation topic is too broad in the first instance.
Factors that make a dissertation topic too broad
Some of the factors that suggest your dissertation topic is too broad include: (a) the research questions you have devised are too open; (b) you are trying to address too many research questions and/or hypotheses; (c) you have included too many concepts, theories, and/or variables; (d) the population you are interested in is too broad to target effectively; and (e) there is no identifiable outcome to your dissertation. Each of these is discussed below:
The research questions you have devised are too open
You are trying to address too many research questions and/or hypotheses
You have included too many concepts, theories, and/or variables
The population you are interested in is too broad to target effectively
There is no identifiable outcome to your dissertation
The research questions you have devised are too open
All dissertations address some form of research question, whether this is a quantitative, qualitative or mixed methods research question [see the section on Research Questions]. When you come up with your idea for a dissertation topic, it should be based around trying to address one or more of these research questions.
Devising research questions that work for your dissertation topic is a difficult task. However, since you will have to clearly state the research questions you intend to answer in both your dissertation proposal and the first major chapter of your dissertation (usually Chapter One: Introduction), it is important that they are not too open. If they are, the reader may think that the dissertation topic you have selected is too broad.
When we say that a research question is too open, we mean three things: First, there may be a lack of precision in the way that your research questions have been written, which makes it difficult for the reader to identify exactly what the dissertation is trying to achieve. Second, the goals of the research may be too ambitious, such that it is unlikely that you will be able to answer your research questions in the timeframe available (i.e., dissertation research at the undergraduate or Master's level often lasts between 6 and 9 months; give or take a few months). Third, the research questions that you have set may be theoretically weak, failing to build on or draw from any established concepts or theories. Let's look at each of these issues in turn:
There may be a lack of precision in the way that your research questions have been written
Whether you are trying to answer a quantitative, qualitative or mixed methods research question, there are structures and styles that you can follow to ensure that these are written in a precise way. In this respect, precision means that the reader knows exactly what you are trying to achieve in your dissertation.
For example, taking a quantitative research question, you would need to show the reader the type(s) of quantitative research questions you are trying to answer (i.e., descriptive, comparative and/or relationship-based questions); and the variables you want to measure, manipulate and/or control (i.e., your independent and dependent variables). You would also need to structure your research questions in a way that helped the reader understand the type of research question(s) you were addressing and the names of your dependent and independent variables [see the section on Quantitative research questions]. You research questions will lack precision when they are unable to communicate these important points about your intended research. To make this more obvious, you may even want to tell the reader what type of research questions you are trying to address (i.e., descriptive, comparative and/or relationship-based question) and the variables you are addressing, in addition to writing out the research questions.
The example above relates to quantitative research questions. Therefore, you will need to read the articles on qualitative and/or mixed methods research questions if you need to know how to more precisely write these types of research question. However, the key point is that a lack of precision in the way that you write out your research questions can make them appear to be too open; and therefore, too broad.
The goals of the research may be too ambitious
It is easy to set dissertation goals that are too ambitious, especially if you have not completed a dissertation before. In our article, How do I know whether my dissertation topic is achievable?. we set out a number of factors that highlight why dissertation topics are sometimes unachievable. When you think about your own goals, you need to ask yourself:
Is it realistic to think that I can tackle a topic of this size and breadth in the timeframe available?
Can I get the access I need to people, organisations, data, information and/or facilities?
Do I have the right skills to achieve these goals, and if not, will it be possible to get the intellectual help I need from my supervisor, other academics, and so forth?
Trying to achieve too much in such a short timeframe is often a sign that your goals are too ambitious. This is often the case if your research involves a length data collection process, whether this is through primary research (interviews, focus groups, questionnaire collection) or secondary research (accessing data). Remember that you may have a number of other assignments and deadlines taking up your time, which you will need to balance alongside your dissertation.
The research questions that you have set may be theoretically weak
Sometimes, the research questions that you have set may be theoretically weak, failing to build on or draw from established concepts or theories.
To understand what this means, research questions are typically either underpinned by (i.e., build on) or related to (i.e., draw from) theory in some way.
We use the words underpinned by (or build on) theory because in dissertations that use a quantitative research design (especially those guided by a post-positivist research paradigm), the purpose of the research is typically to test and/or build theory, often using a deductive approach [for an introduction to these concepts, see the section on Quantitative research designs]. Simply put, this means that these kinds of dissertations are strongly underpinned by theory. In fact, the testing and/or building of theory may be the main purpose behind your dissertation in such cases.
We use the words related to (or draw from) theory because in dissertations that use a qualitative research design (which may be guided by one of a wide range of research paradigms), the purpose of the research is not necessarily to build or test theory. In fact, these kinds of dissertations more often use theory to help guide the research process, as well as explain the findings from the research that is conducted. As a result, the research questions that are set may be related to one or a number of theories, but it may not be immediately obvious how the two - research questions and theory - are connected.
The key point is that if your supervisor (and/or the person marking your work) cannot see a connection between your research questions and some established theory or concepts, your research questions may be viewed as being theoretically weak. Being theoretically weak is a problem not just of research quality, but it can also mean that your research questions are too open and too broad. If you are unsure what established theory or theories either underpin or relate to your research questions, perhaps they have not been fully thought out.