Summary Findings Outcomes data on both elementary- and middle-grades youth showed that program-based and other structured after-school experiences, along with adult supervision, improved youths’ conduct and work habits during the two-year study period. Survey data indicated reduced misconduct among those in structured, supervised settings, compared with their unsupervised peers. When elementary-grades youth assessed their work habits, all three supervised clusters reported improvements over two years, in comparison with youth in the self-care plus activities cluster . Among middle-grades youth, the three supervised clusters reported relatively less substance abuse at the end of the second year, compared with the self-care group. Middle-grades youth in the program plus activities and program only clusters showed moderate improvements in work habits, relative to youth in the self-care plus activities cluster. Teachers of elementary-grades youth confirmed that those who participated in high-quality after-school programs and other adult-supervised experiences fared significantly better than did their peers who were unsupervised after school.