It's not just that the freshmen look younger every year.

A report released Wednesday shows that 57 percent of colleges now enroll high school students in courses for credit. The National Center for Education Statistics released the report, which was designed to examine the breadth of "dual enrollment" programs.

These programs allow high school students to take courses at colleges -- for credit at both levels of education. The idea is to challenge high school students and to promote a better transition from high school to college.

While 38 states have policies that allow such dual enrollment, there has been little data on the impact of these policies in higher education. The report found that:

• Of the 57 percent of colleges with high school students taking credit courses, 85 percent had dual enrollment programs and 55 percent had high school students who took courses outside formal dual enrollment programs.
• Participation varied by sector of higher education, with 98 percent of public community colleges, 77 percent of public four-year colleges, and 40 percent of private four-year institutions enrolling high school students.
• Larger institutions were more likely to have high school students enrolled than smaller institutions were. At institutions with at least 10,000 students, 94 percent had high school students, but the percentage drops to 83 for institutions with enrollments of 3,000-9,999, and to 44 for institutions with enrollments below 3,000.