It is customary these days, for students pursuing a doctoral degree in a scientific discipline, to co-author a number of articles published in peer-reviewed, international scientific journals, during the course of their studies. In many disciplines, the widespread expectation is that by the time doctoral candidates are ready to take the final exam, their curriculum vitae will sport a number of publications, most of which with them as leading authors and/or in high-impact journals in their field of study.
In the early years of their graduate training, student publications typically arise as a result of them being involved in existing research efforts, often times under the lead of another, more senior student. As they progress with their own research project, students publish landmark results of work to which they contribute more and more substantially, in fact eventually becoming the main investigators thereof. This work, in turn, forms the core of their doctoral dissertation.
There are many good reasons for encouraging graduate students to publish their work during their time in school; but, there are also potential dangers with pushing too far the notion that the number of published papers should be the ultimate, or even most important measure to gauge a student’s progress. In particular, I regard as meaningless and pernicious the idea of a minimum number of published manuscripts (three, four or however many) as a de facto requirement, in order for a student to be ready to graduate — an idea ostensibly popular among faculty and students alike (it is often phrased as “a dissertation should be worth three papers, each one corresponding to a chapter — plus introduction, methodology and conclusions”).
First of all, why should students publish ? I can think of the following reasons:
0) Scientific publication is how work is communicated and disseminated throughout the community. There is no substitute for it, and any scientist worthy of this name must be capable of doing just that — communicating effectively in writing the outcome of a scientific experiment or calculation, as well as providing an appropriate description of the work carried out. And it is not only about writing articles. A significant fraction of the time spent by a professional scientist goes to writing — proposals, internal reports, and even documents aimed at a general audience. Writing articles turns out to be an excellent training ground for that kind of writing.
The job of teaching a graduate student how to write a clear, concise and informative scientific article, rests with the student’s major professor but, as in everything else, practice makes perfect. That means that it is a good idea to have a student go through this exercise periodically. Granted, an advisor could ask for a simple “internal” progress report, to be written for the exclusive benefit of the advisor and the student’s supervisory committee. Chances are, however, that that will not entail the same level of rigour, thoroughness and precision that is expected of an article that will undergo peer review. There is a lot to be said for the process of going through the literature, trying to place one’s work in the broader context of the collective effort of the community, comparing results to those of others who have carried out similar investigations, understanding the possible implications on and connections to someone else’s research, thinking of future developments .
1) A published article is in many respects a milestone, marking the completion of an important intermediate step toward a more ambitious, comprehensive final goal. Its authoritative significance, offers a reasonably impartial, objective assessment of the progress made by a student. Among other things, it provides some factual basis for a supervisory committee, a department chair, a scholarship evaluator, to extend the support of that student, in light of the progress made.
It can also have the effect of reassuring and boost the morale of the student, by giving him/her “something to show” for all the work done up to that point, as opposed to fearing that sleepless nights in the lab or at the computer may all be for naught.
2) Want it or not, publications remain the most important hallmark of one’s scholarly activity, they are what makes our work known to society (at least the segment thereof with which we interact), and they constitute the basis for evaluation of an academic scientist for hiring, tenuring and promotion purposes. It seems good practice for students who aspire to pursue the academic route to start building a respectable publication list as early as possible.
Having said the above… one also must be very wary of any attempt, or any (un)stated practice on the part of a department or individual faculty, of setting a minimum number of co-authored articles as a requirement for graduation.
Yes, I have witnessed cases of students graduating with a PhD without a single published article, and while that may not be the optimal outcome, it can happen, and it should not be taken as a partial failure. Conversely, I have seen students who had co-authored a relatively large number of publications, well above the average for graduate students in their field, who in my opinion did not possess the level of knowledge and scientific maturity that a “doctor” should have — some of these students actually struggled to finish their PhD, and did not really get very far in research thereafter.
I am occasionally in the position of hiring a postdoctoral collaborator myself, and I routinely pass on candidates with a large number of publications, opting instead for others with a shorter CV. There are many possible reasons why the latter may give me a stronger impression, e.g., through their research statement, in their interaction with me, with the way they talk about their work, their presentation skills, their imagination, and so on.
There are circumstances in which publication of the outcome of doctoral research work simply is not possible, for a number of valid reasons. However, this should be at least in part divorced from a dispassionate, objective assessment of whether a PhD candidate should be granted the degree sought. In other words, while lack of publications can be a bellwether of weak research skills, and therefore the reasons should be ascertained, it need not mean that.
Here are a few personal considerations, in random order:
0) Publishing a paper does not have any thaumaturgic effect. One does not wake up one day a scientist, just because article number three (or, whatever) has appeared in print. Whether or not a student is maturing, becoming a confident scientist and a valuable asset to a research group, is something that a PhD supervisor must assess by observing the person on a daily basis, over the course of a few years.
1) Any “minimum number” rule puts undue additional pressure on students who are already trying to get as much done as possible in a limited time.
2) More importantly, such a rule cheapens the pursuit of a doctoral degree, i.e., a complex, multi-faceted and life-changing endeavour, by reducing it to mere accumulation of co-authored papers, when there is so much more to it than that. In my opinion, if a student can carry out research over the course of 3 years to the satisfaction of his/her major professor and supervising committee, showing competence and maturity, the capability of interacting profitably with other scientists and talking knowledgeably about his/her field, deliver effective presentations and write a clear, exhaustive dissertation — all of that by itself is worth a doctoral degree. If on top of that there are publications, so much the better, but if for whatever reason the output has been less than initially hoped for, to no fault of the student, that student ought not be held hostage to some “publication dogma”.
3) Insisting that a number of articles be published before completion of the degree, has potentially unfair effects on students in some specific disciplines or sub-fields thereof, in which the magnitude, scope and duration of research projects make it especially hard to publish a lot. An obvious example is experimental high energy physics, with experiments whose build-up can easily take several years and publishable data may not even be available within a reasonable time frame for completion. Should that mean that graduate students in that area should accept from the start that their time in graduate school will be longer than for their colleagues, for reasons over which they have no control ?
4) Lest we forget: this is research, which means, sometimes things simply do not work out. Experiments do not yield useful data, maybe they were not well thought out to begin with, theoretical approaches fail to yield any novel insight. I maintain, however, that there is a chance for students to grow into respectable science professionals, even working on doomed projects.
5) Contrary to popular belief, the academic route is not what the totality, or even the majority of doctoral candidates, aspire to. Many of them are actually interested in pursuing one of the many alternative careers that are available, for example in industry. Emphasis placed in industry on publications is nil. So, why should doctoral candidates who have demonstrated the analytical and technical skills, as well as the knowledge of the field that is expected of a doctor in their area, be prevented from graduating over an extra paper, given that the impact that these papers will have on their future career is nil ?
6) Again in that “Contrary to popular belief” vein, sheer number of papers has long ceased to be (if it ever was) a criterion for hiring of postdoctoral associates or assistant professors, for tenuring and promotion, for prize conferral etc. Things like actual impact of published papers (measured, for example, by number of citations, or speaking invitations received by the students connected to those works), prestige of the journal(s) where papers are published, how many co-authors, the role played by the person in the various works, all of that greatly outweighs the mere count. Again, no reason to hold a doctoral candidate to a standard that society deems inappropriate anyway.
 An immediate consequence of this reasoning, is that for the purpose of evaluating a student’s maturity, published papers should be assessed differently depending on the actual contribution given by the student to the writing of the manuscript.