Yale admissions officers are ratcheting recruitment efforts up a notch this year as they prepare to encourage early acceptees to the class of 2012 to matriculate next fall.

The new recruitment strategies — which include the expansion of the “adopt-a-prefrosh” program — are part of the office’s annual re-evaluations and cannot be chalked up to any one factor, Admissions Director of Outreach Jeremiah Quinlan said. But the changes come in a year when admissions officers have acknowledged that it will be unusually difficult to predict the percentage of students that accept Yale’s early admission offer, since two of the University’s peer institutions eliminated their early programs this year.

The admissions office’s “adopt-a-prefrosh” program, which provides personalized attention to admitted students, will reach out to about 400 students, more than four times as many early acceptees as it did last year, Quinlan said. More students accepted regular decision will also be “adopted” this year, but the increase is proportionally much smaller — from 270 to about 400 this year.

The program — which was first used to recruit the class of 2011 — assigns current Yale students to e-mail and call a handful of accepted students, offering to answer their questions and sharing their own experiences at Yale. The office solicits unpaid Yale volunteers through e-mails and matches them with students who have been randomly selected from the pool of admits.

In response to a large volume of volunteers this year, the program has been able to more than double its size, Quinlan said. This year, about 200 Yale students volunteered, while 90 volunteered last year, he said.

The program will also shift away from last year’s focus on students admitted regular decision, Quinlan said, and will instead divide attention equally between early action and regular decision admits. Last year, Yale students “adopted” one high school student accepted early action and three accepted regular decision, while this year, they will adopt two of each, he said.

Although admissions officers declined to link the changes to concerns about Yale’s yield from early action, Dean of Undergraduate Admissions Jeff Brenzel said earlier this month that the decisions of Harvard and Princeton universities to discontinue their early admissions programs beginning with the class of 2012 will make it harder to predict the University’s yield.

Students who prefer Harvard or Princeton might have applied early to Yale — contributing to the 36 percent increase in early applications over last year — but intend to enroll at Harvard or Princeton if accepted. As a result, Yale may have to work harder this year to retain students accepted early. Still, Quinlan insists the new strategies are not a direct result of the changing early admissions climate.

“None of our newer programs were instituted in response to other institutions, but rather to better serve our admitted students and provide them a variety of different opportunities and sources of information,” Quinlan said in an e-mail.

Earlier this year, admissions officers also flirted with the idea of a February Bulldog Days — exclusively for students admitted early — that would supplement the current Bulldog Days in April, Quinlan said, but that proposal is now off the table.

The proposed February Bulldog Days would have intended to give students admitted early a chance to bond with fellow admitees and explore Yale before regular decisions were mailed, Quinlan said.

But the admissions office ultimately decided against the event, Quinlan said, because of the amount of time that would be required to plan it as well as concern that it would detract from the size and atmosphere of the existing Bulldog Days in the spring.

“We think that having all the admitted students on campus at the same time probably creates the most excitement and gives all admitted students the best sense of who else will be coming to Yale if they choose to matriculate,” Quinlan said in an e-mail.

Yale has had a larger increase in early applications this year than Stanford University as well as Brown and Dartmouth universities, the only Ivy League schools that have released admissions data so far.

At Stanford, the admissions office had received 4,504 applications for its nonbinding early action program as of Nov. 14, compared to 4,574 last year, according to The Wall Street Journal.

Stanford Dean of Undergraduate Admissions Richard Shaw, who served as Yale’s dean of undergraduate admissions for 13 years before moving to Stanford in 2005, did not respond to a request for comment.

Brown received 2,449 applications for early decision this year, up nearly 6 percent from last year, according to the Brown Daily Herald. Dartmouth received a record 1,397 applications, 8.7 percent more than last year, according to The Dartmouth. Both schools have binding early admissions programs.

Most of the half-dozen high school guidance counselors and college consultants interviewed said, in their experience, persistent recruitment efforts play an important role in convincing students on the fence to matriculate.

“My impression is that all the personalized attention works,” said Jon Reider, college counseling director at San Francisco’s private University High School. “Everyone knows that Yale’s a great school, but Yale also wants to be seen as friendly and welcoming. That’s what’s going to coax students to come.”

But Wade Boggs, college counselor at the Westminster Schools, a private institution in Atlanta, said the very act of being admitted early is often more important to students than an admissions office’s outreach. Imagining oneself at a school for several months creates a mental image that is often hard to shake come March, Boggs said.

Actually visiting the campus — and living like a Yale student without work for a few days — convinced at least a few of this year’s freshmen to enroll.

Tia Wantchekon ’11 said current Yale students were helpful in answering her questions over e-mail, but what tipped the balance for her was attending Bulldog Days in April.

“I just loved it,” Wantchekon said. “That’s what made the final decision for me.”

Last year, Yale accepted 1,860 students out of the 19,323 total early and regular decision applicants for the class of 2011, for an acceptance rate of 9.6 percent.