What is a dissertation and how is it different from a thesis?
As promised in the Season 4 preview, this is the first in a series of episodes on the written product of many graduate degree programs: the thesis or dissertation. There are roughly as many dissertations written each year as there are PhDs awarded. According to ProQuest – the leading online repository for theses and dissertations in the United States – there were a little over 49,000 PhD dissertations submitted to the archive in 2024, representing about 85% of the some 58,000 PhDs awarded that year according to the NSF Survey of Earned Doctorates. Not all institutions have strict dissertation publication requirements and not all require a copy to be uploaded to ProQuest. But, you can see that there are roughly 50,000 PhD dissertations produced in the United States alone each year. By comparison, there were under 600 full-length movies released that year, and between 2.5 and 3 million scientific and engineering research papers published worldwide. So, the number of dissertations falls somewhere in between these two examples, yet they are accessed far less frequently than either. Then why do we even have dissertations? What purpose do they serve?
Let’s start at the beginning. The word “dissertation” comes from Latin meaning a discussion or discourse. As such, it is a term that can be used very broadly to describe any type of exposition on a topic, though it usually implies an in-depth description rather than a perfunctory statement. And, a dissertation need not necessarily be written under this definition. But in academic circles, a dissertation is indeed a written document on a scholarly research topic, often required for the doctorate. In fact, most dissertations include language on the title page to the effect of “submitted in partial fulfillment of the requirements for Doctor of Philosophy…” blah, blah, blah.
But that’s true of a thesis, too. What’s the difference between a thesis and a dissertation? It depends. The answers range from “nothing” to “opposites of one another,” depending on where you are. In the U.S., the dissertation is a doctoral-level document whereas a thesis is generally used for master’s-level documents. It’s the opposite in the U.K., however, where “thesis” is used to describe a doctoral project. Which is why we generally use the combined term “theses and dissertations.” It’s not ideal, but it’s what we have. I’m going to use the term “dissertation” here because I’m located in the U.S. and because I want this series of podcasts to focus on the outputs of doctoral education. But what is true for dissertations is broadly true for theses, even those written by undergraduates.
Etymology and usage aside, the dissertation takes on many forms depending upon the disciplinary subject, but it is generally true that it is used as the basis for a faculty-led committee to judge independent scholarship of a degree applicant. There are no hard-and-fast rules about how a dissertation should be organized, but most graduate schools have established guidelines and minimum requirements like these. Note that there are very few required pages, but those that are have very strict formatting stipulations. In fact, templates are often provided for these pages to help you conform to the institution’s requirements. Nothing will get your thesis or dissertation rejected faster than a missing title page or abstract. Gone are the days when there was a real live person who took out a ruler and measured the margins of a thesis to make sure they met requirements – I’m dead serious – but there are still some requirements for these documents so carefully read the rules your institution provides before you start. There’s nothing worse than trying to get your dissertation accepted by the graduate school while you are starting a new job and HR is asking for a copy of your diploma or transcript that is being held up because you forgot a table of contents. But we’re not going to dwell on these picayune details. We’re here to talk about the scholarly content of a dissertation and how it might be logically presented.
Let’s look at three common dissertation formats: the protomonograph; the series of papers; and the written exhibition. There are certainly other formats and the dissertation is evolving, but those are topics for another day. Today, let’s focus on what formats are currently in fashion by way of examples. For copyright purposes, I am pulling only dissertations that I was able to find publicly online without any subscriptions or institutional access. In most instance I’ve redacted some identifying information – even though I don’t need to because these are “fair use” examples – because I want to focus on format and organization rather than the individuals or their intellectual contributions. In other instances, the identity of the author is important to the format of the dissertation. Let’s start with such an example from the social sciences.
The Protomonograph
“Protomonograph” might be a new term for you. It certainly was for me as a new graduate dean coming from the engineering sciences. But I quickly learned that the dissertation can serve different secondary purposes beyond “partial fulfillment for the doctor of philosophy degree.” Scholarship is about dissemination of new information and ways of thinking. Without that dissemination the work sits in an academic vacuum. There are many ways to disseminate one’s scholarship, including journal articles, oral presentations at conferences, and mainstream media interviews. But in the humanities and social science disciplines, one of the very important methods of information dissemination is books. People read books. They like to keep them, share them, quote from them, and scribble in them. One specialized type of book is the monograph – a small(ish) publication on a narrow topic, usually but not always written by a single author and often but not always published by a university publishing house. The monograph is the “coin of the realm” for the humanist or sociologist, especially if they seek a career as a professor. It used to be said that one book will get you tenure, and a second book will get you promoted to full professor. I’m not sure how true – or useful – that adage is any more, but book publishing is still a large part of many professors’ research output and there’s no better source for launching a monograph than the dissertation.
Here’s a recent example from the discipline of history. I’ve unmasked the identify of this author not to promote anyone’s work, but because it illustrates my point clearly. The book “Yuppies” by Dylan Gottlieb was published this year by Harvard University Press. Dylan Gottlieb received his PhD in American History from Princeton University in 2020 and is now an Assistant Professor at Bentley University in Massachusetts. “Yuppies” clearly derives from his dissertation. How do I know without reading both documents? Just compare the tables of content. The books are similarly organized with similarly-titled chapters. Again, this is not a review of the content – this is simply a demonstration of how a dissertation can be parlayed into a monograph. Sometimes that second book for promotion also comes from the dissertation, though there are varying opinions on the novelty of this approach insofar as it being “new” and “independent” scholarship is concerned. At any rate, it is common for dissertations in disciplines such as history, sociology, and political science to be turned into monographs.
There are downsides to the dissertation as monograph approach, not least of which is the disappearance of the academic publishing houses along with open faculty positions, as well as the inaccessibility by the general public to these types of scholarly contributions, but I save those topics for another day. Suffice it to say that if your research advisor produced a monograph from her dissertation, chances are that this will be the expectation for your dissertation as well.
Publication-Based Theses and Dissertations (PBT)
The second type of dissertation format comes from the science and engineering disciplines. The quest for objectivity compels me to explain this style of dissertation, but let me state up front that as an advisor and committee member for dozens and dozens of theses and dissertations in the engineering sciences, I really despise this format. More on that in a bit, but what I mean by a “series of papers” is basically the approach taking the two or three (or more) peer-reviewed articles that you have published in the course of your research and assembling them into a single document, often bounded by an Introduction at the beginning and a Conclusion at the end. But not always …
Here’s a lightly-redacted example in the chemistry discipline from my undergraduate alma mater – the University of Illinois at Urbana-Champaign. It is an extreme example of the publication-based format, insofar as there are only two main chapters, each a stand-alone publication, with additional publications in the appendix. The first chapter is cited as a reproduction with permission of a copyrighted journal article, which the dissertation author listed as a co-author. This raises the first problem of the article-based approach: attribution of work. If you go to the actual article on which this chapter is based, it indicates that both first co-authors contributed equally to the work, as many publications indicate these days. Fine. This isn’t a question about authenticity of work, it’s a question of how one values this publication in assessing the scholarly contributions towards a PhD. Should 50% of a co-authored, peer-reviewed article be treated differently than 100% of a single lead authored publication? Whose idea was it really? Is this a collaborative team for the duration of the research, and if so, is this a joint dissertation as opposed to a single author dissertation? These questions may be rhetorical but academia is struggling with them nonetheless as the dissertation continues to evolve. Stay tuned for more of that in the next Episode of Grad-post! But continuing with our example, the second chapter has no such citation to a published journal article, so presumably it is a single lead-author publication that may or may not be submitted in the future. The appendices are other related publications by this author, and if you look in the dissertation, they are the actual reprinted articles, just like you would find if you looked them up online. Again, fine. But what percentage of these works are the author’s, and if they are not a main part of the dissertation then how are they to be assessed and valued in the context of a dissertation defense? Is it simply “more is better?” Again, these are rhetorical questions about the validity of this formatting approach, not of the work itself. All these publications are in prestigious journals with excellent impact factors. The works are well cited and this author already has an excellent citation record. The subsequent dissertation defense based on these publications was obviously sufficient for the committee to award the degree – just as was the case with the protomonograph – so the dissertation format was not a detriment. You will find more and more of this approach in the science and engineering disciplines in the coming years, and your research advisor may even demand that you use this format.
What I object to most about this format – other than what I’ve already mentioned - is that it often omits two very crucial elements of a scientific study: hypothesis testing and broader impacts. Not all scientific studies need follow a strict hypothesis-testing approach. There are alternative approaches to scientific inquiry like creative discovery, but even then there is often some higher principle guiding the research. In either case, there should be some statement of purpose, whether that is a formal hypothesis or simply a justification for why the study was undertaken and what the investigators expected to be found. Similarly, the broader impacts address such issues as societal impact, applications or implications to other fields of study, and even future work. A “traditional” scientific format – one that includes an introduction, literature review, experimental materials and techniques section, and results and discussion followed by a conclusion – creates a logical narrative by which the hypothesis is stated, tested, then either accepted or rejected, including findings beyond the central premise. A collection of journal articles can do this, too, but repeated sections like the literature review, experimental techniques, and conclusions are at best disjointed and at worst redundant. The disassembly of multiple publications in an attempt to create self-standing introductory and conclusory sections creates a clunky document that doesn’t faithfully represent the independent scholarship its author is trying put forward as partial fulfillment of the degree of doctor of philosophy. Enough of my whining. If your advisor gives you a choice of how to present your research in your dissertation, opt for the traditional structure over stapling your papers together. The extra effort will bring a holistic perspective to your scholarship that it otherwise would not have had. That benefits you if nobody else.
A Written Exhibition/Performance
Finally, there is the dissertation format I call the written exhibition, typically found in the fine and creative arts. In many instances it is still a critical analysis, but it could also be documentation of a performance or a creative work in and of itself. Here’s an example of a dissertation in music composition. It’s basically just the musical composition – the score. There is still a title page, an abstract, and a table of contents as required by the institution. Notice that the table of contents comprise only the composer’s notes, the performance notes, and the score which is just the two movements of the piece. It’s very different than some of the other dissertations we’ve talked about, yet it is just as much a scholarly work. What makes this musical composition worthy of a PhD and not something I just generated on Suno? I’m not a musicologist so I can’t give the scholarly answer to that, but the people on the dissertation defense committee can. And just like it was for the other dissertation formats, their expert opinion is good enough for me.
As in all of these examples, it was my responsibility as graduate dean to make sure the people advising young scholars and serving on dissertation committees were qualified. That doesn’t mean approving every member of every committee; rather, it meant having policies and procedures in place to assure the credentials and qualifications of the individuals serving on dissertation committees. Assuming that my counterpart at this institution does the same, then if these committee members say that this work qualifies for partial fulfillment of the degree of Doctor of Philosophy in Music Composition, then as a member of the academic community I accept their judgment. Similar arguments can be made for dissertations in theatre and dance, graphical design, and even in a few areas of studio art typically limited to the master’s of fine arts degree.
We’ve covered most of the disciplinary bases in this podcast, though certainly not all. From the humanities and social science to the engineering and science disciplines to the creative arts, theses and dissertations can take on different formats, but they all have one thing in common: the documentation of new knowledge. Such is the purpose of the PhD in general and the dissertation specifically.
https://about.proquest.com/en/products-services/pqdtglobal/
https://ncsesdata.nsf.gov/builder/sed
https://www.statista.com/statistics/187122/movie-releases-in-north-america-since-2001/
https://grad.illinois.edu/academics/thesis-dissertation/format-requirements
https://thehonores.com/3-million-papers-a-year-is-academic-publishing-out-of-control/
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