The website for Texas Christian University's business school features a photo (above) of students holding signs denoting various rankings for the M.B.A. program.

But the TCU business school no longer has any rank at all from U.S. News & World Report. That's because it gave incorrect information about standardized test scores to U.S. News -- and that information was part of the basis for its ranking.

U.S. News announced that TCU originally reported fall 2017 average scores of 678 on the Graduate Management Admission Test, when the real average was 640. (The originally reported score is typical of fairly competitive business schools; the actual average score is not.) TCU reported the problem to the magazine.

GMAT average counts for 16.25 percent of the formula U.S. News uses to rank business schools. As a result of the score error, U.S. News removed its ranking of the TCU business school.

David G. Allen, associate dean of the TCU Neeley School of Business, said via email that the incorrect data were the result of human error. "A person on our team who provides rankings input inadvertently entered the wrong GMAT data in the average GMAT score field," he said. "We have internal processes for checking these data, but did not catch this error prior to publication."

In the last year, a number of questions have been raised about the reliability of data used for various business school rankings.

U.S. News removed the ranking of Temple University's online M.B.A. program following the disclosure it was based on incorrect information on the percentage of students who submitted GMAT scores. Temple is now investigating the possibility that four years of rankings may have been based on incorrect reports.

In December, a data breach revealed that Stanford University's business school, which has boasted of giving only need-based aid, had in fact been awarding some aid based on factors other than need.