CAMBRIDGE, Mass. — When the Massachusetts Institute of Technology acknowledged 12 years ago that it had discriminated against female professors in “subtle but pervasive” ways, it became a national model for addressing gender inequity.

Now, an evaluation of those efforts shows substantial progress — and unintended consequences. Among other concerns, many female professors say that M.I.T.’s aggressive push to hire more women has created the sense that they are given an unfair advantage. Those who once bemoaned M.I.T.’s lag in recruiting women now worry about what one called “too much effort to recruit women.”

Much as a report accompanying M.I.T.’s acknowledgment more than a decade ago offered a rare window on an institution tackling gender discrimination, the new study, being released Monday, shows how thorny the problem is — and not just at M.I.T.

“It’s almost as though the baseline has changed, because things are so much better now,” said Hazel L. Sive, associate dean of the School of Science, who led one of the committees writing the report. “Because things are so much better now, we can see an entirely new set of issues.”