“Why would we change our way of doing this ? After all, we have done it this way for years…”
(haven’t we all heard these words many times ?)
The writing of the dissertation is traditionally a culminating moment for a doctoral candidate. After completing a number of demanding courses, writing exams and, over the course of a few years, building a research portfolio and having matured as a scholar in a specific field, a PhD candidate is expected to “put it all together”. His/her thesis will be examined by the advisors and the committee members, and defended by the candidate him/herself at the doctoral exam.
Writing a thesis is a challenging task; one need only look at the number of blogs devoted to the very tribulations experienced by PhD candidates during the process. To be sure, it has also served a valuable purpose for many years, as a worthwhile intellectual exercise, for a number of different reasons.
However, I think that the circumstances in academia have evolved over the past few decades, to the point where in some fields, e.g., in the sciences, I am no longer sure that there is a real need, or even a point, for students to spend a significant portion of their last year in school writing a comprehensive recount of their graduate work.
It is a tradition probably almost as old as academia itself, and some aspects of the ritual can be actually quite enjoyable, and rich in educational value. When I started out as a PhD student myself, each dissertation defense (PhD exam) was a departmental event, attended by the majority of faculty and students, to make it even more memorable a day for the graduate. I remember how awe-inspiring and motivational was for me, a beginning graduate student, to attend the first defense (in my experience, it is not quite the same these days, as much of the solemnity is gone, and often one is talking a mere formality, largely ignored by the department and quickly disposed of by the few involved).
And there was a time when the thesis was the first major piece of writing done by young scholars. Only at that point would they finally have the time to review thoroughly the existing literature pertaining to the subject of their study, attempting to assess the relative significance and novelty of their contribution, in the process laying the ground for a possible journal publication. The thesis could then be used later on as a foundation for further research, or as a canvas for a research proposal. Along the same lines, the defense was the first important talk given on that subject before an audience not consisting only of the advisor and fellow graduate students or postdocs in the same group. In many respects, it could be regarded as a rehearsal for the same talk, given later on at a conference, or at the freshly minted PhD’s new place of work.
These days, however, things do not quite work that way for most PhDs. In the sciences, e.g., in physics, graduate students become involved early on in tasks such as writing manuscripts for publication, or research proposals. By the time a student is ready to go through the defense, (s)he has typically published at least two articles in specialized journals, given already one or two talks (or at least presented posters) at major international conferences, contributed to the writing of research proposals, and generally seen his/her work undergo intense scrutiny from leading scientists in his/her field, whose evaluation can be expected to be far more thorough (and competent) than that of committee members and other departmental faculty (most of whom are no experts in the candidate’s field of research). In other words, there is little need these days for departmental vetting of the research work done by a PhD candidate, especially given the high degree of specialization of most scientists.
Very seldom do graduate students, even at second-tier institutions, work in isolation, without substantial interaction with the outside world. The markedly international and collaborative character of most research conducted nowadays, results in students traveling extensively during their studies, both to attend meetings as well as to do part of their work elsewhere, in collaboration with fellow students and faculty at other institutions . If to that one adds the easy access to online preprint archives and journal articles that students enjoy these days, far greater than that at the disposal of the average graduate student even a mere fifteen years ago, one understands why most graduate students are well-aware of the status of their field, know all the main players and the seminal papers, and hardly need to go through the exercise of summarizing all that in that very time-consuming chapter called Introduction.
My impression, based on my experience both as a graduate student and as a faculty, as well as on countless conversations with colleagues and friends, is that a PhD thesis these days consists for the most part of a compilation of all articles published by the students, often reprinted almost verbatim . Most of the time, aside from writing the introduction and the conclusions (which are just a repeat of the introduction), is spent with issues of formatting (universities are quite finicky about it), printing, binding and all that.
And who is going to read the thesis ? Hardly anyone, besides the candidate and the advisor, and maybe committee members (though I think most of them just go through the introduction and the conclusions). It will lay then somewhere untouched through the years, and will typically not be counted as a publication for most relevant purposes .
Not surprisingly, students would rather spend the time working on another project or writing another actual publication, than on what they regard as a bureaucratic, mostly formal “rite of passage” with little substance. I can’t blame them, I am wondering whether maybe the time has come to abandon this vestige of a time past, maybe to replace with something more in tune with current practices.
 Indeed, it is often this network of contacts, which graduate students begin to develop early on in their career, that eventually leads to their first post-graduate appointment.
 This can actually be done in accordance with well-defined university procedures. As long as a formal statement is made at the beginning of the chapter, explaining that the material is reprinted from published work, there is nothing wrong or unusual about that.
 I have heard colleagues argue that a PhD thesis can be used by future students to bring themselves to speed on that subject of research. I wonder how often this is the case, and even whether that is a good way to go about it. Things change, each new thesis project brings about fresh knowledge, and often times one wonders whether it is best to let new students rework some of the stuff by themselves, possibly improving on what was believed to be “optimal”.