How do matters lie with the polygraph dissertation?

I’ve been thinking lately about dissertations. The traditional model is for a PhD student to write a book-length exploration of a topic. A newer model is for the student to write several publishable papers on related topics. I’ve heard the former called the monograph dissertation, which naturally makes the latter a polygraph dissertation.¹

I have met some philosophers who are hostile to the polygraph dissertation, but not for any clear reasons. I’ve met others who welcome the new model. As someone advising graduate students, I would like to have a better sense of what the disciplinary norms are.²

I recently learned that some other disciplines which have adopted the papers model (such as computer science and public health) explicitly require three publishable papers. My sense is that philosophers, even ones congenial to polygraphic dissertations, would want to see more than three papers.

This isn’t entirely separable from the question of how big a paper needs to be. I’ve known people who wrote monographic dissertations and then just published one over-sized monster of a paper based on it.³ David Ozonoff, who is at the BU School of Public Health, writes, “Like most institutions with the three paper option, we don’t accept ‘least publishable unit’ [LPU] papers as fulfilling the requirement. Each paper of the three must represent a meaningful contribution to the field.” This means that “each paper is like a mini-monograph” and a papers dissertation can be harder than a monograph dissertation. The traditional model of the dissertation becomes like a hydra, recapitulating its faults in each of the papers.

Although I understand why Ozonoff dismissively mentions LPUs, I find them to be a helpful concept for thinking about articles. An over-sized monster paper covers too many separate issues, too many LPUs. So a reader with a different background will probably be in no position to get anything useful from it— they are unlikely to read the monster, and unlikely to notice the part that would be useful to them if they did read it. Since the person who wrote the dissertation has spent years working out their views, everyone else has a different background. If the monster were carved into separate contributions, then readers who would find part of it useful might actually get it.⁴

Let’s suppose that the papers must be something deeper than a discussion note but less sweeping that a mongraph. For the sake of mock precision, suppose each must contain between 1.5 and 3 LPUs. My question, then, is how many it should take to make a dissertation. Comments welcome.

1. I’ve also heard them called a narrative dissertation and a papers dissertation (respectively), but that doesn’t make for a catchy title.
2. I wasn’t reflective about it when I wrote my dissertation, but I leaned toward polygraphy. I had an overarching framework, but it carved the project into smaller parts which came out of or went into numerous papers.
3. In contrast, parts of my dissertation were incorporated into at least nine different papers: Thing #1, thing #2, thing #3, thing #4, thing #5, thing #6, thing #7, thing #8, and thing #9.
4. None of the papers which incorporated parts of my dissertation presented the whole framework which held them together in the dissertation itself. Everytime I started to sketch it out in a particular paper, I realized that driving this nail didn’t require the whole hardware store.