DES MOINES (AP) - The University of Iowa is informing 184 students and graduates that their grades and perhaps their Social Security numbers were on a laptop stolen from a former teaching assistant.

The computer contained class records for students who took the teaching assistant's philosophy courses between 2002 and 2006. Social Security numbers were listed for 100 students, the university reported.

School officials said they have analyzed backup copies of the files and found them an unlikely source for committing identity theft because the Social Security numbers are difficult to locate.

Students affected were in sections of "Philosophy and Human Nature," "Philosophy and the Just Society," and "Principles of Reasoning" taught by Tuomas Manninen.

The computer was stolen last month from Manninen's home in Arizona, the school reported.

The U of I dealt with a similar incident in June 2006, when a professor's laptop was stolen in Davenport. That laptop contained personal information of 280 current and former students.

School officials said at the time they were trying to reduce the use of students' Social Security numbers.