The Massachusetts Institute of Technology said Thursday that admissions dean Marilee Jones — a crusader for reducing the anxiety around college admissions — has resigned for misrepresenting her academic credentials to the university. Jones, dean since 1997, has been a highly visible campaigner for reforming the college admissions process. She issued a statement saying she had misrepresented her credentials when she first came to work at MIT 28 years ago and "did not have the courage to correct my resume when I applied for my current job or at any time since.