Congressional researchers visited 25 programs in six states and wound up identifying three successful approaches for dropout prevention: Supplemental services, which provide additional counseling, tutoring, or other help for students who may be at risk of dropping out; alternative learning environments, such as Las Vegas High's Partnership at Las Vegas program, that put selected groups of students in settings outside the main student population; and school-wide restructuring, in which administrators change the overall organization or curriculum of a school.