Wellesley College Dean of Admission Janet Lavin Rapelye will become dean of admission at Princeton as of July 1, Princeton University officials announced Thursday.

Rapelye will replace Fred Hargadon, who has headed the Princeton Admissions Office for the past 15 years. Before her 12-year stint as dean of admission at Wellesley, Rapelye worked in admissions at Williams College, Stanford University and Bowdoin College. As dean, she will face a newly-instituted entering class size, as well as ongoing national debates over affirmative action and early admissions.

Rapelye was chosen from among 75 applicants for the position, said Princeton Dean Nancy Malkiel, who chaired the search committee. Malkiel said all the applicants were very qualified, but that Rapelye stood out as the candidate most capable of handling the 11 percent increase in entering class size to be instituted in 2006.

“We had a group of outstanding candidates and it was our judgment, in the end, that she was the most impressive among them and the one best suited to meet the needs of the admissions office in the years to come,” Malkiel said.

Rapelye said she is excited to join the Ivy League and said she thinks her experience at other schools will help her in the new post.

“I’m thrilled about going to Princeton,” she said. “I’ve been in the field of admissions for about 20 years — I’ve been able to see admissions done a number of different ways — there’s not just one way to admit students to a school.”

Rapelye said plans to spend the upcoming year getting acquainted with the Princeton admissions process, rather than making any broad changes.

“I’m looking forward to getting to know the staff,” she said. “I’m not expecting to institute any major changes in the next year or so.”

This year, Hargadon decided to withhold early decision admit numbers. Rapelye said she was not yet sure whether she would continue this policy, but said she understands the importance of open communication.

With the April 1 Supreme Court hearing of the University of Michigan affirmative action case approaching, Rapelye said said she hopes that the Supreme Court will support affirmative action.

“I am hoping that the courts grant the most amount of flexibility to admissions offices in higher education and that they permit us to continue practicing affirmative action,” she said. “It is so important to have students from every background being able to take advantage of our incredible resources, and if that were limited in any way, I think that would compromise our mission.”

Rapelye said she expects the debate about early admissions, another hot topic this year, to be carefully looked at across the nation over the next few years.

“I think that deserves attention right now,”she said. “It’s the mend it or end it question — is there a way we can fix this, or do we have to end it. That is not clear yet in the field.”