Disadvantaged students who regularly attend top-notch after-school programs end up, after two years, academically far ahead of peers who spend more out-of-school time in unsupervised activities, according to findings from an eight-state study of those programs. Known as the Promising Afterschool Programs study, the new research examined 35 programs serving 2,914 students in 14 communities stretching from Bridgeport, Connecticut, to Seaside, California. The programs, all of which had been operating at least three years when the study began, were selected because of a record of success. For advocates of after-school programs, the results offer a counterpoint to a controversial 2005 evaluation of the 21st Century Community Learning Centers program, a federal initiative that finances after-school enrichment programs for 1.3 million elementary and middle school students nationwide. Conducted by the Princeton, N.J.-based Mathematica Policy Research Inc., the earlier study found that the federally funded programs provided no special learning boost and may even have led to a slight statistical increase in some negative behaviors.