I wrote the first part of this about a year ago, soon after I got tenure. I got bogged down and it remained unfinished until now. Enjoy.
So I have this job where after a set period of time—in my case, 6 years—my employer had to make a decision either to fire me, or to promise never to fire me. The latter thing is called "tenure", and seems to be pretty widely misunderstood. This note may help clear up some of the confusion…
In the beginning (of the modern system), colleges were places where groups of wealthy students would contract with instructors to teach on a per-course basis. It rapidly became a difficult model to sustain, and colleges self-organized into permanent faculties with a more standard curriculum.
One of the problems with all such arrangements is that it is difficult to teach things the students should know, but that are unpopular with society and even with other college faculty. Students demanded better; the academic freedom to keep unpopular teachers around as long as they were basically doing their job of teaching. Thus tenure, the pledge of permanent employment, was born.
Now of course there have to be some checks and balances, or many faculty members would do as little work as possible, or even bad things. The chief mechanism adopted to combat tenure abuse is a tenure-track probationary period, typically around six years. During this period the untenured professor, usually given the title of "Assistant Professor", tries to demonstrate their willingness and ability to do their job. The college in turn decides, most often on a year-by-year basis, whether to retain the professor; it is rare that a college will terminate a professor before the end of the tenure period, but not unheard-of.
When the prescribed probationary period is up (or occasionally earlier in the case of especially promising professors) a tenure decision is made. To prevent the college stringing a professor along on an untenured basis indefinitely, one of the choices offered to the college is not to delay the tenure decision; rather, the college must either guarantee the professor tenure or dismiss them. If tenure is granted, the professor is usually granted "Associate Professor" status and a sabbatical, a vacation-like period with partial pay in which they may tackle new research, complete projects, earn some extra money, and/or just take a rest. (Sabbaticals are then granted every seventh year for the remainder of the professor's career.) A professor denied tenure is likely to be given a contract for one more year to "teach out" and find another position inside or outside academia.
The tenure decision is almost always the result of a multi-stage process. First, the tenured faculty of the professor's department, or some subcommittee thereof, makes a recommendation through some sort of voting process. This recommendation is then often referred to the department Chair, who makes a recommendation based partly on the faculty recommendation. This recommendation is passed in turn to the Dean of the professor's college unit, who makes a recommendation based on it. The Dean's recommendation is passed to the college Provost, who in turn writes a recommendation to the college President.
For those keeping score at home, that's a chain of five recommendations that comprise the tenure decision. As you might expect, it is quite uncommon for anyone in the chain to reverse a recommendation to deny tenure. It is also infrequent that a recommendation to grant tenure is reversed, but it does happen. Thus, a tenure-track professor needs to make a tenure case that will make everyone in this chain happy, especially their faculty promotion and tenure committee.
A college's tenure guidelines are always encoded in some kind of formal document. They consist of criteria in three broad areas: research, teaching, and service. For most institutions service, the professor's work-related activities assisting the department, college, professional field, or community, is given small weight. Unless the professor has been phenomenal in this area, their service will not significantly affect their tenure recommendation. The teaching/research balance is a function of the individual institution; at most institutions these days research will be weighted more strongly than teaching, but depending on the institution it might be close.
One of the reasons that research gets such a strong weight in many tenure evaluation processes is that it has two very visible metrics. The frequency and quality of the professor's refereed publications is fairly easy to measure; it is assumed that a professor that is publishing is doing good work and enhancing the reputation of the college. Since money is the most valuable resource at almost any institution, and a measure of the respect funders have for a professors work, a professor's funding is also considered quite important, and certainly reduces to a nice neat little dollars-per-year number. At many colleges, a certain level of funding and publication is a fairly explicit requirement for a professor seeking tenure.
Teaching is much harder to evaluate. Quantity of teaching is straightforward, but one presumes that quality also matters At many institutions, much weight is given to the students' reports of a professor's teaching quality, in spite of the well-known and awful biases introduced by this approach—students' evaluations are strongly correlated to the course grade they receive, and strongly correlated to the desirability of the courses being taught. Woe to the Assistant Professor stuck teaching an undergraduate "weeder" required course.
While the official three criteria of tenure are important, it is also important to realize that the process is hard to nail down; if some influential person or small group decides to block the tenure of an aspiring professor, it is easy for them to justify doing so. Thus, another criterion that is key is simple collegiality and the enthusiasm of the faculty and administration for the professor's work. As one of my colleagues once told me, "When I am voting on a tenure decision, I first consider whether I'm willing to spend the next twenty or more years working with this person."
Once a professor is tenured, there is very little that can be done to fire them (especially at an institution like mine where the professors are also unionized). Typically, the only grounds for dismissal are serious felony-level criminal misconduct or utter long-term neglect of the usually-minimal contractual duties of a faculty member. As long as the tenured professor turns up to teach classes and keeps out of prison, the job is almost always for life. In particular, and in spite of common misconceptions, the jobs of tenured professors who engage in inappropriate sexual or drug-related behaviors with students are almost certainly safe as long as they are not convicted of a related crime.
The tenure system is truly problematic—something that I've said all along, but especially since I received tenure (B). The system's original goal, protection of professors teaching controversial content, is largely inapplicable in the case of the hard sciences and engineering, where professors mostly shouldn't be teaching "charged" content anyhow. The system is occasionally horribly abused by professors. Perhaps more troubling, the often bizarre and arduous six-year tenure track ordeal can disrupt the lives of professors, often at the most productive point in their careers. The tenure evaluation process is often superficial and arbitrary; those who have committed six years of their lives to the profession when things take a bizarre turn are often devastated. Those who earn tenure in science and engineering tend to be the types who would be employable outside the institution with much better compensation—for them, the "reward" for tenure might be essentially a lifetime guarantee of a job they aren't sure they even want.
On the plus side, in my department the result of the process has been to select a faculty that I am proud to work with and whose work humbles me constantly. Some mistakes of omission and inclusion are made at every institution. However, the process does tend toward an upward spiral of personal and institutional success, which is probably why it has been retained so long and thoroughly. I can't imagine a process like tenure working in industry. In the colleges, it seems to kind of work. I find this remarkable.
I feel fortunate and honored to have received tenure at my institution. Hopefully this note will help outsiders understand what tenure means, and will be a guide to those who are where I was some eight years ago—starting the long march through the tenure process. (B)