LUBBOCK, Texas -- Texas Tech University is investigating allegations that the grades of several students in the Rawls College of Business were changed to unfairly improve their results and allow them to graduate.

Jay Conover, the tenured professor who taught the course, noticed that some grades listed on the transcript for the students were not the same as what he issued. He attended graduation ceremonies and was surprised to see that three of the MBA students received their diplomas anyway. A fourth student is set to graduate at the end of the summer semester.

Conover said that D's were changed to A's and B's, while a C was changed to an A. He learned the business college's dean had signed off on the students' change-of-grade form, which didn't list any reason for the grade switch.

When students typically appeal their grades, Conover said the dean forms a committee in which students and the instructor appear, but that didn't happen in this case. He said that the students in question had approached him near the end of the spring semester to ask him for a better grade so they could meet the GPArequirement to graduate.

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But he said told them they would have to retake the course if they wanted to get their degree. Conover said that he met with the dean in April to discuss the students' low grades. The dean showed him emails from the students, whose grades were changed, that blamed their low grades on poor teaching.

Conover said he believes their academic performance had stemmed from taking too many courses during the semester.

Provost Lawrence Schovanec said in a statement that school officials are looking into the allegations.

"We will not have further comment until the review is complete," he said.