The research did not examine the full range of foreign students in the United States. It did not include graduate students or students who transfer to four-year institutions from community colleges, intensive-English courses, or so-called pathways programs.

Yet over all, the findings do suggest that American colleges need to do a better job of dealing with the mismatch between the expectations international students have of studying in the United States and their experience once on an American campus, said Sheila Schulte, Nafsa’s senior director for international enrollment management and international student and scholar services.

College recruiters should be upfront about academic requirements and about what it takes to succeed in an American college classroom, Ms. Schulte said, especially with students who come from very different educational backgrounds. They should also be transparent about college costs and financing, she said. If campus jobs are limited, for instance, international-admissions officers should make that clear to foreign students, who are forbidden under United States law to work off-campus.

In addition, international-student advisers may need to collaborate more with other campus offices, such as career services, to make sure those offices are prepared to handle the special needs of foreign students, Ms. Schulte noted. More than a third of the students surveyed singled out access to jobs and internships as one of the most effective ways to retain students.

Despite those concerns, retention and graduation rates for international students remain high — in many cases, higher than those of American students. More than 60 percent of the baccalaureate and master’s institutions surveyed and more than half of the doctorate institutions said their retention rates were higher for foreign than for domestic undergraduates.

Still, as the number of students from overseas continues to increase — the Institute of International Education reports there are 40 percent more foreign students at American colleges than a decade ago — their retention rates bear watching, Ms. Schulte said.