Freshmen at Slippery Rock University of Pennsylvania won't get flagged by the calorie police if they react to classroom stress by loading up on ice cream in the dining hall.

But if they swipe their meal cards too few times early in the school year, their eating habits will trigger a different kind of scrutiny. Within days of those skipped meals, they can expect a visit from a residence hall assistant, checking to see whether their transition from high school to college has veered off course.

Such "early-alert" strategies are part of an effort to improve the first-year experience that has helped Slippery Rock raise the share of freshmen who make it to their sophomore year from 69 percent a decade ago to nearly 80 percent now.

Nationwide, colleges have never been more aware of the risk that a student's freshman year will be his last. On average, one student in four at four-year campuses leaves school before sophomore year; on two-year campuses, the rate is 50 percent. Some will enroll elsewhere, but others will drop their degree pursuit.

To stem the exodus, nearly every campus offers at least a freshman seminar in which students learn study skills such as time management and are introduced to resources including the library.

Many of those schools, including Slippery Rock, a state university with 8,000 students, go much further, offering to house new arrivals with classmates who have similar interests, ensuring that students can take more than one class together, and even sending them off to climb ropes in teams.

"There are some out there who would probably say we're holding hands, but we have a retention-rate improvement that has gotten us a lot of respect," said Amanda Yale, Slippery Rock associate provost for enrollment services.

It's no surprise that class attendance and grades are watched. But so are dining hall visits during the first 15 days of classes.

"It's an easy way to know if, A, they're not here or, B, they are just hanging out in the room ordering pizza or playing video games, doing things other than assimilating into campus life," said George McDowell, a Slippery Rock recruitment and retention strategist.

If students are foundering, it's better to respond in September than November. As time goes on, he said, "It's harder to climb uphill."

Under a light drizzle, Slippery Rock freshman Kaitlynn Poston and 10 peers toiled one afternoon last week on a rain-slick obstacle course designed to promote teamwork. Afterward, the 18-year-old from Butler said making friends was "scary but exciting" and that her adjustment was going pretty well.

Not far away, freshman Matthew Rapp, 18, of West View, put down a dining hall tray long enough to share a common freshman worry: "I don't want to just start ignoring homework and reading. I did that a little bit in high school. I know that if I do that in college, I'm going to get destroyed."

Freshman programs, which range in length from weeks to two semesters, take various forms and can be optional or mandatory, depending on the college. Viewed by some during the Vietnam era as a way to discourage campus unrest, the programs' proliferation in the decades since reflects a dramatic shift in thought on whose job it is to ensure that a student thrives.

The sink-or-swim notion of the freshman experience fit well in an age when college was the path for a select group. Nowadays, with college virtually a prerequisite for middle-class life, each student who falters is a drag on an education system struggling to churn out enough qualified workers.

And every freshman who leaves is a student whom campus recruiters must spend time and money to replace.

Research suggests the programs have impact. One review of studies by Penn State University's Patrick T. Terenzini and the University of Iowa's Ernest Pascarella indicated that those finishing seminars are 5 percent to 15 percent more likely to graduate in four years.

But advocates of the programs say it's not simply a matter of keeping classroom seats filled.

"Retention is a minimum standard. It's a C-minus and a pulse" to continue on in college, said John Gardner, executive director of the Brevard, N.C.-based Policy Center on the First Year of College. "Why not have a vision for excellence in the beginning of a student's college experience?"

At Carnegie Mellon University, freshmen in humanities and social science enroll in seminars with 15 to 20 students and receive what the school calls "an intellectually exciting" introduction to faculty research and teaching. Carlow University says goals for its first-year-experience course include connecting students to the college's mission and history.

Dr. Gardner said seminars tend to work better if students in them also share at least one other class during the year. Sessions team-taught with a student leader tend to be more relevant to students. And the more credits awarded, he said, the greater the student benefits. Therein lies a problem.

"The majority of the courses in the country are only one [credit] hour, which means the majority of these seminars are from the get-go less likely to provide the kind of outcomes you would ideally want," he said.

That's not an issue for students at the University at Albany in New York who enroll in Project Renaissance. Its 12 credits satisfy a significant share of the General Education requirement.

At California University of Pennsylvania, which has seen its own sizable retention gains, a strong message is sent early on by where part of freshman orientation is held: inside the headquarters of the tutoring and academic support center.

At the University of Pittsburgh, it's not just 18-to-22-year-olds who get attention. First-year help for adult learners includes a "mastering the university" program in which students attend campus activities, see a career counselor and learn about financial aid.

Older students worry less about fitting in socially than about seeing a clear link between campus effort and career goals, said Sherry Miller Brown, director of the McCarl Center for Non-Traditional Student Success.

They are motivated but easily frustrated by early failures.

"The most compelling problem we have is students who are agonizing over their math," she said.

So she delivers a "guerilla math" seminar. "I walk them through some of the myths, such as women can't do math. There's a bunch of them."

Not everyone sees first-year seminars as a panacea. Faculty at some schools are uneasy about varying standards and unsure how strongly they correlate with success.

Starting next year, Penn State locations other than the main campus will no longer be required to have a first-year seminar. Instead, those locations can decide for themselves whether to include one as part of a mandated student-engagement plan.

Among the reasons was a belief by some that a chief objective -- ensuring that freshmen can take at least one small class -- is less of an issue at Penn State's smaller branches.

At Slippery Rock, the school's first year program factors into decisions campus-wide, from the number and type of student life activities offered, to how much study-table time is required of freshman athletes. Weeks into the semester, students are asked in surveys whether they are getting what they need academically and socially.

And a student majoring in, say, biology is liable to be in a freshman seminar taught by a professor from the department. That's because students unafraid to approach professors are more likely to succeed.

"Getting to know two or three faculty members," Dr. Yale said. "That's a key."