A typical thesis will motivate why a new idea is needed, present the cool new idea, convince the reader that it’s cool and new and might apply to the reader’s own problems, and evaluate how well it worked. Just like a paper!
The result must be a substantial, original contribution to scientific knowledge. It signals your official entrance into the community of scholars. Treat it as an chance to make a mark, not as a 900-page-tall memorial to your graduate student life.
The cynical view is that if you’ve written several related papers, you staple them together to get a dissertation. That’s a good first-order approximation — you should incorporate ideas and text from your papers. But what is it missing?
First, a thesis should cohere — ideally, it should feel like one long paper. Second, it should provide added value: there should be people who would prefer reading it to simply reading your papers. Otherwise writing it would be a meaningless exercise.
Here’s what to do after stapling:
integrate the pieces
- craft a substantial introductory chapter that ties the work together and highlights the novel contributions
- reorganize the remaining presentation into a series of chapters that support and develop your story from the introduction
- write a (brief) concluding chapter that recapitulates your story and summarizes what was learned
- make the notation, terminology, and style consistent throughout
- do keep good ideas, text, and results from your previous papers (giving credit to any co-authors)
expand the text
- make the text clearer, more tutorial, and more thoughtful
- add more examples and intuitions to help the reader
- add new experiments/theorems/significance tests to leave no stone unturned
- consider counterarguments, variations, and alternative explanations
- give enough details to allow a reader to replicate the work or apply it in new settings
contextualize the ideas
- open the thesis with a page or two that sells the work to a general audience (e.g., a science reporter)
- mention all obviously related work and explain how it relates to yours
- discuss alternative solutions that you rejected or are leaving to future work
- point out connections to other areas, including other possible applications of your ideas
- describe possible generalizations (and try them if possible)
- lay out future work for yourself or others
acknowledge help (usually in a preface)
- acknowledge any collaborators on this work, such as your advisor
- acknowledge financial support on this work, and perhaps also other financial support you’ve received as a grad student
- thank other people who have helped you technically, administratively, socially, or emotionally over your grad student career
- state which parts of the thesis text (if any) have appeared in your previous publications; get permission to republish if you are no longer the copyright holder of those works, or if you had co-authors
Don’t expect your advisor to be your co-author. It’s your Ph.D.: you are sole author this time and the responsibility is on your shoulders. If your prose is turgid or thoughtless, misspelled or ungrammatical, oblivious or rude to related research, you’re the one who looks bad.
You can do it! Your advisor and committee are basically on your side — they’re probably willing to make suggestions about content and style — but they are not obligated to fix problems for you. They may send your dissertation back and tell you to fix it.
In the following sections, I’ll start with advice about the thesis as a whole, and work downward, eventually reaching small details such as typography and citations.