Carnegie Mellon University didn't waste any time. Two days after irregularities about the awarding of a master's degree came before the administration, the university accepted the resignation of a prominent dean.

One thing's for sure: CMU is not WVU.

Yet the departure Friday of Mark Wessel, dean of the H. John Heinz III School of Public Policy and Management, leaves some key questions unanswered.

The university said the case stemmed from "an error in judgment involving the approval of excessive transfer credits and excessive units for independent study in lieu of course work" for a student who received the degree in 2004. Carnegie Mellon said concerns about the degree were brought to a faculty member, who checked the student's records and then notified President Jared Cohon. Citing federal privacy laws, the university said it is not releasing the student's name or the type of degree that was awarded.

That still poses a few questions in the minds of students, faculty and others.

Why did it take four years for the case to surface? Did Dean Wessel know the student personally? Did any other university official know the degree was being awarded based on these credits? Does Carnegie Mellon have a system that independently double-checks the certification of credits for a degree?

Although Carnegie Mellon believes this was an isolated case, spokesman Ken Walters said it is reviewing the records of other degrees. To its credit, the university informed the Heinz School faculty and staff of the dean's resignation at a meeting on Friday and sent an e-mail to students and alumni.

"We always take any issue regarding academic integrity very seriously," Mr. Walters said Monday. "This is something where, when we find out something like this, we review it immediately."

That appears to have been done, and Carnegie Mellon should be applauded. It took a different approach from that of West Virginia University, which this year had its own episode with a suspect degree -- a case that first was kept secret, then became public, protracted and embarrassing.

Even so, more information from Carnegie Mellon describing the circumstances of this unusual academic breach would dispel questions left in the minds of those on campus, not to mention alumni and donors.