In mathematics, preceptors must pass five-yearreviews but may stay indefinitely. In East Asianlanguages and Slavic languages, preceptors maystay eight years and also have the chance to bepromoted and remain indefinitely if they can passfive-year reviews.

The end result of the four-year rule isturnover perhaps more massive than anywhere elsein the Faculty of Arts and Sciences.Administrators spend much of their time readingdossiers, placing ads and recruiting around thenation for new teachers. In a given year, nearlyone-third of the teachers are new.

"There are some people who don't have a clueafter the first year," says James D. Wilkinson'65, director of the Bok Center for Teaching andLearning. "Good teachers ought to be retained.There aren't so many good teachers in the worldthat we can go throwing them out after fouryears."

But the administration publicly backs the Expospolicy. Buell says he likes the rule for manyreasons, including the fact that it "maximizes ourutility to replenish" the teaching pool.

"The obvious cases where good teachers are letgo early are more than compensated for [by thefact that] so-so teaching was allowed tocontinue," Buell said. "[In a more lenientsystem,] are you going to chop the head off ofrespectable mediocrity? The odds are that you'regoing to reserve the axe for blatant cases."

But teachers say Buell's response is deceptive.They point out that they work on one-yearcontracts, which do not have to be renewed. Onlylazy administrators incapable of making toughdecisions need a four-year rule to get rid ofmediocre teachers, teachers say. If anything,keeping a stopwatch on teacher's tenure encouragesaverage performance.

"Most of the time what the rule leads to ismassive mediocrity," says one Expos veteran."People walk in the door looking for another job."

"Human psychology being what it is, it'sdifficult to feel any investment in a departmentwhere you learn the ropes the first year, sailthrough the second year and by the end of thethird year, you're thinking about your next job,"says Philip A. Gambone '70, who has taught Exposfor two years and is now on leave. "It seems to meit would be worth the department's while to try tocreate an experienced, competent, collegialfaculty."

The administration does not present a unitedfront on the four-year rule.

One source in the Faculty administration calledthe decision to impose the limit a "mistake."

Asked if he could name one way students wereserved by the four-year limit, Robinson Professorof Celtic Languages and Literatures Patrick K.Ford '66, a member of the standing facultycommittee on Expos, thought for a moment.

"No," he said.

The four-year rule is not the onlychange in Expos hiring policy in recent years thathas met with criticism from teachers.

Sommers and Marius say it has become theirexplicit goal in the last few years to hire asmany teachers with Ph.Ds as possible. In the past,Marius sought to hire practicing writers. Theshift, he says, is part of an effort to"professionalize" the department and make Exposmore academically credible.

According to documents obtained by The Crimson,in the spring of 1989 only seven of the 42 peopleteaching Expos classes had Ph.Ds. Last spring, 24of 40 held Ph.Ds.