Marilee Jones, the dean of admissions at the Massachusetts Institute of Technology, became well known for urging stressed-out students competing for elite colleges to calm down and stop trying to be perfect. Yesterday she admitted that she had fabricated her own educational credentials, and resigned after nearly three decades at M.I.T. Officials of the institute said she did not have even an undergraduate degree.

“I misrepresented my academic degrees when I first applied to M.I.T. 28 years ago and did not have the courage to correct my résumé when I applied for my current job or at any time since,” Ms. Jones said in a statement posted on the institute’s Web site. “I am deeply sorry for this and for disappointing so many in the M.I.T. community and beyond who supported me, believed in me, and who have given me extraordinary opportunities.”

Ms. Jones said that she would not make any other public comment “at this personally difficult time” and that she hoped her privacy would be respected.

Ms. Jones, 55, originally from Albany, had on various occasions represented herself as having degrees from three upstate New York institutions: Albany Medical College, Union College and Rensselaer Polytechnic Institute. In fact, she had no degrees from any of those places, or anywhere else, M.I.T. officials said.