The University of Pittsburgh School of Law's national rankings by U.S. News and World Report have had as many dips as a roller coaster.

Its lowest point in more than a decade was 93rd in 1997. In recent years, its highest was 47th, released in 2004.

Since then, the school's rankings have been mostly falling, from 52nd to 60th to 57th to 73rd in the rankings released last week. While Pitt is still in the first tier, that's a drop of 16 places in a year.

"It's very frustrating when there is a ranking system that has been as dominant as U.S. News has been that doesn't capture the underlying quality," said Mary Crossley, in her third year as dean.

Nor is Don Guter, in his third year as dean of the Duquesne University Law School, satisfied that his school is the last of four tiers despite the fact its students last summer had the second highest pass rate on the Pennsylvania bar exam.

Law schools love to hate the annual rankings, but they are used by many students in selecting a school and can make-or-break an administrator's career.

They are important enough that Ms. Crossley sent an e-mail to Pitt law students, acknowledging they may find the drop "distressing," but noting: "It does not mean that the quality of the education that you are receiving at Pitt Law has declined over the past year."

She cited top honors won by a legal blog edited by law students, increased bar passage rates, a strong ranking last fall for faculty's scholarly impact and broadened employment opportunities, including an increase in graduates accepting out-of-state jobs

Most law school deans have signed a letter that goes out to candidates, discounting the value of the rankings, said Mr. Guter.

At the same time, some schools spend thousands of dollars sending out glossy brochures during the fall balloting to try to increase votes and hence their rank.

"On the one hand, the deans are fighting to try to have a better measure of quality or not to have one so commercially driven. On the other hand, we're all caught up in it," said Mr. Guter.

Both deans were happy with rankings of some specialty areas. Pitt came in 13th in health law, and 28th in intellectual property law. Duquesne ranked 30th for its legal research and writing program, its first numerical ranking in the report.

The rankings rely on five basic categories: 25 percent for reputation among law school deans and faculty, 15 percent for reputation among lawyers and judges; 25 percent for selectivity; 20 percent for job placement and 15 percent for faculty resources.

Robert Morse, director of data research for U.S. News and World Report, said the rankings are just "one tool" and should not be used exclusively in making a decision.

Mr. Morse said Pitt's ranking declined because its scores in faculty resources, job placement and reputation among lawyers and judges had declined. The others stayed about the same.

Ms. Crossley noted that a number of schools are clustered close in points to Pitt, resulting in small changes making bigger differences in rank.

On a 100-point scale, schools with just one more point ranked five places higher than Pitt did.