Double duty: growing numbers of high-school students are enrolling in college--while they're still in high school.

ANCOUVER, Wash. -- Brittni Samman was still a sophomore at Davenport High School, about 30 miles west of Spokane, Wash., when she decided she would start college the following September.

Some of her classmates and even a few teachers warned her against the plan. They told her she was rushing her future and would miss out on the high-school activities and events that are so often the highlight of a teenager's life.

Nevertheless, with some trepidation, Brittni enrolled. Now, the 17-year-old has 40 college credits under her belt, a new glow of self-confidence and plans to be a psychologist.

Brittni is one of a growing number of high-school students participating in the explosion of dual-credit and concurrent-enrollment programs nationwide that some say represents the most significant advancement in education since the Head Start program of the mid-1960s.

"This is probably one of the best educational movements in the country," said Dr. Hans Andrews, former president of Olney Central College in Olney, Ill., and one of the nation's biggest cheerleaders for dual-credit and concurrent-enrollment programs.

Making the Leap

"Running Start," "Project Excel," "Bridge," "Project Advance," "Fast Forward," "Project Challenge": The energetic-sounding names of dual-credit and concurrent-enrollment programs vary from state to state and even district to district.

But in a nutshell, most dual-credit or concurrent-enrollment programs allow high-school students--typically in their junior or senior years--to take collage-level courses on their own campuses or at local colleges and to receive credit at both institutions. In some cases, students complete enough credits to earn degrees from their high school and community college at around the same time.

For the most part, programs follow one of three formats: Classes taught by college instructors at the college campus and attended by a mix of students; …