Often the past business experience of students can be counted on to help carry the day's case study. The unwritten rule of B-School admissions requires two years of work experience before matriculation, and each first-year section contains a diverse mix of former managers, consultants and engineers.

In fact, students are sometimes assigned cases that they have already studied in their past employment training. In November 1987, a case appeared on the marketing midterm exam which 22 students had previously encountered at their Bain & Co. orientation. Before selecting the case, the professor failed to make a routine check on whether Harvard had already sold copies of the case to the Boston-based firm.

Changing the Professor's Role

Student participation, together with the fact that much information on each topic is presented directly in the case, allows professors with little expertise in the field to conduct classes nonetheless. Some say this frees professors to teach and learn about a variety of subjects, but critics maintain that the B-School's expertise in methodology comes with a loss of expertise in subject matter.

Ford Professor of Business Administration Michael C. Jensen says that he came to recognize the merits of case teaching--even before coming to Harvard-when he taught at the University of Rochester's lecture-oriented Simon School of Management.

"My transition to using cases actually started about a decade ago," said Jensen. "I moved to being more of a moderator, a coach and a guide. I somehow or another stumbled onto the importance of it at Rochester, but [at the B-School] I learned how to do it better."

"The learning experience is largely a burden that students carry, not the professors," says Jensen, "which is not a bad rule." However, Jensen adds that for faculty, "it's easy to lay back and be protected form ignorance by the ethic in the classroom that you're not expected to provide the answers."

To teach at the B-School, "You don't have to know the subject. You just have to know the case method," says Ciulla. "One benefit is that professors can teach something they're not experts in. But on the other hand, people come in expecting to be taught by experts."

Students, though, say they are not disturbed by these conditions. Given the structure of the case method, they have come to judge professors by their ability to direct discussion, and not by their lecturing skills.

If the professors have little connection with a topic, says one first-year student, "it doesn't make such a difference. With 90 people in the class, you usually pick up someone who's been in the business before. The teachers whom people think don't have any credibility are the ones who don't cut off the conversation when it becomes just a bunch of spewed answers."

The Case Study Factory

The B-School plays a dual role in case studies--it not only uses them extensively in its own courses, but also is the major supplier of case studies to business schools and corporations around the world.

Harvard maintains a collection of 6000 cases, of which 2000 are used exclusively by Harvard professors, officials say. All have been developed at the B-School, and most are written by full-time case writers under faculty supervision.

The school distributes three-and-a-half to four million copies each year; one-and-a-half million are used within the B-School alone. Up until the 1950s the school served as a clearinghouse for the case studies of outside institutions, but later it abandoned this role.

The B-School has also helped other Harvard graduate schools to utilize the case study method. B-School professors last year helped Harvard's Medical School make its New Pathways program--a case-based system of instruction initiated as a 24-student experimental project four years ago--the foundation of its curriculum. The School of Public Health and the Kennedy School of Government also use the case method in some of their courses, says Christensen.