A commenter asks:

Care to share any sage advice on the dissertation process (how to get it done, considerations in selecting an outside committee member, etc)? Since you’ve already gotten the Ph.D. I thought maybe you’d have some good insights…

There have probably been dissertations written about writing dissertations; Getting What You Came For is a fairly standard reference, and one I recommend. That said, specific advice from my little corner of the universe follows:

• Getting it done: there’s an adage that once you really start working on the dissertation, it will take six months to write. I wasted most of the latter half of 2001 (from my comprehensive exams in September/October) and early 2002 putting together what may be the worst dissertation prospectus known to man. I then fiddled about with a conference paper or two that would eventually comprise the substantive dissertation chapters for about a year. Finally, in May 2003 the catalyst arrived: I went to a family reunion and decided the collective prodding of the PhDs in the extended family was enough to make me write… and so it was; I defended the first week of December 2003, and my PhD was conferred on the 13th, the day before my birthday.
  On days I decided to write or do data analysis—and this happened in fits and starts—I would go and make myself work in the library to minimize distractions, even if I was only going to play with R or Stata. Most people recommend formally setting aside time to write, and it’s something I agree with—and wish I did more of now.
  I also think you need to be in the right psychological state to write. Even if you’re not prone to psychological disorders (and a friend of mine who’s a psychologist says that really smart people are particularly prone to these problems, for reasons not fully understood), a bit of therapy during the writing process—if only so you have someone neutral to complain about your advisor to—is a good thing.
• Outside member: I lucked into a good choice by happenstance: my final semester taking classes, I had a multivariate stats class in the pharmacy administration department and met a prof over there with whom I established a good rapport. He turned out to have valuable comments on my work, even though it was pretty far afield from him substantively. Having an outside member who you can trust is a nice security blanket. Don’t do what Frequent Commenter Scott did and end up with some externally-imposed outside member who you have no prior relationship with. I don’t have any experience with having someone from the same field but a different institution on the committee (and I’ve never served on a committee in either capacity), so I can’t speak to that.

On the prospectus itself, I’d recommend having a clear idea of what you’re doing and why before writing it. In my case, I put together a half-assed cut-and-paste job from the lit reviews of some papers and it showed—the fact that nobody bothered to tell me what they wanted in the prospectus was no excuse for me not finding that out for myself. If I’d had a clearly thought-out prospectus, I’d probably have finished much earlier. Admittedly, in my case, I was still young when I got done, but it would have been nice to be younger. Oxford’s nice enough, but getting out of there a year earlier would have been helpful (for my wallet, if nothing else).

Last, but not least, expect things to change throughout the dissertation process. Originally I thought I was going to do an experiment in one chapter and focus more on heuristics throughout the dissertation; in the end, it ended up being more about information processing and cognitive sophistication and their roles in attitude formation, opinion articulation, and behavior, which turned out to be a far more interesting topic and one that seems relatively underexplored in the literature, although a lot of really smart people seem to be getting at the edges of these questions—I like a lot of Alvarez and Brehm’s work, as well as Jon Krosnick’s. (But I digress in a very political-sciencey direction.)