“What do I need to put in the conclusions chapter of my thesis?”
This is probably the most commonly asked question about thesis writing other than questions about using the first person singular. (About the latter: it’s your thesis. Use the first person sparingly, but if you really want to emphasize that something is your opinion or your idea, go ahead, provided your thesis advisor doesn’t object. Some of them really have a problem with first-person writing. It was probably beaten into them as graduate students.) The good news is that it’s not that hard to write the conclusions chapter, but it is a bit of work because it requires that you go back to the beginning.
The first thing you’re going to want to do is to write a section that summarizes the major findings of your thesis. You should generally start this section by reminding your readers of the major question(s) or hypotheses that you started with. Go back to the part of your introduction where you laid out your questions or hypotheses. (You did have such a section, didn’t you? If not, you need to write that, probably near the end of your introductory chapter before you lay out the plan of your thesis. These questions or hypotheses should follow logically from your introduction to the problem area contained in the introduction. But I guess that could be the topic of another blog post.) Paraphrase your original question(s) or hypotheses, then summarize how your thesis addressed these. As you are writing this, keep notes about any ways in which your thesis may have stopped short of fully answering your question(s). You will need these later.
This section tends to be highly variable in length from one thesis to the next, depending on how efficiently you summarize your work. For some types of theses, this section can be a few paragraphs. In other cases, it runs to several pages. You want to review major lines of evidence (not every single calculation or experiment) and how they contribute to your conclusion. Your conclusion should be stated reasonably precisely. Your conclusion may be any of the following, depending on how things worked out:
- Here is the answer to the question I asked or, analogously, I have proven/disproven my hypothesis.
- My work provides a partial answer to the question I asked or, for hypothesis-driven work, my work supports my hypothesis. For this kind of conclusion, you want to make sure you summarize what parts of your questions were answered and therefore what gaps still exist. Don’t go into detail about those gaps here. Just acknowledge them. And again, the corresponding writing for a hypothesis-driven thesis would be to discuss how strongly your work supports the hypothesis.
Your work in context
Your work probably connects to many other issues in your field. If you can, it’s a good idea to try to tie things together a bit in your concluding chapter. This section (or these sections, depending on how much you have to say) will probably have a specialized title emphasizing how your work fits into your field. Is there similar work, perhaps mentioned in your introduction, that your work now puts in a different light? Are there other areas in your larger field where similar issues arise and where your work now provides at least some insights? For example, if you were working on object permanence in pigeons, you could have a section entitled “Object permanence in other vertebrates” where you discuss whether your work provides insights into this problem for the broader field. To do this properly, you would probably need to talk a bit about the evidence showing that object permanence functions similarly across a range of species. You probably did that in your introduction, so here you would briefly remind readers of this evidence before trying to argue that your conclusions might extend to non-pigeon vertebrates as well.
In some ways, this is an optional section, because it won’t always be obvious how your work connects to the rest of the field. I would really want to see some writing along these lines in a Ph.D. thesis. I would like to see it in an M.Sc. thesis, but because of the scope of M.Sc. projects, it might be harder to do there.
Very, very few theses (or scientific studies of any sort) provide completely definitive answers applicable to a wide range of situations. You will want to discuss those limitations, but also indicate that this opens up avenues for future research. You may already have developed some ideas for this section while writing the summary section. However, you now need to go back and reread your entire thesis carefully. This is especially the case if your thesis contains papers to which others contributed. As you are reading, ask yourself these questions:
- What gaps are left by my work? In other words, what parts of my original questions were only partially answered, and how might these gaps be addressed? For hypothesis-driven work, what are the pieces of evidence missing to fully confirm the hypothesis and, again, how might this evidence be gathered?
- What are the assumptions that your work makes, or the approximations used? Might these assumptions or approximations have affected the answers you obtained? If so, what further studies could be done to determine if similar answers would result these assumptions or approximations were removed or modified? Even if you don’t think that your assumptions affected your study, can you imagine studies that would answer different questions by removing these assumptions, or making different ones?
- What questions come to mind as you are rereading your thesis? Sometimes, interesting questions will come to you while reading the review of the literature in your introduction. For example, it might occur to you that your work creates a foundation for studying problems you mentioned there. A discussion of these related problems and how they might be addressed by building on your work could go into the future directions section, or in the work in context section discussed above, but either way this is great material to include. It is very likely that you will find questions that you didn’t touch in the sections of your thesis that report on your work as well. How could they be addressed? You don’t need to write a lengthy and detailed proposal here, but do discuss questions raised, either directly or indirectly, by your work.
- Could the methods or models you developed be built on and used to answer additional questions? For example, if you develop a mathematical model of a process, it is likely that other modeling studies could build on yours, either by applying your model in a different context, or by adding details you left out.
Your thesis contains the seeds of your concluding chapter.
You will notice that I am essentially asking you to comment on things that are already in your thesis, in one way or another. At the point of sitting down and writing the concluding chapter, the raw material for writing this chapter is already written. You just have to go back and read your thesis with your critical and questioning faculties fully active. Take notes about things you might write about as you go, and then sit down and write the concluding chapter based on your notes.
And as everything else about writing a thesis, it’s a highly individualized document. You should try to cover the points I am describing above, but you should feel free to organize the material in a way that makes sense to you, as long as it will make sense to your readers, too.