Findings from five main projects in the National Center on Effective Secondary Schools, which operated from December 1, 1985 to February 28, 1991, are presented. Projects investigated different aspects of engagement and achievement problems through literature reviews, analyses of existing data sets, and new studies of students and staff in 32 middle and 62 high schools throughout the United States. Material from the projects is integrated into the following chapters: (1) "The Significance and Sources of Student Engagement" (F. M. Newmann, G. G. Wehlage, and S. D. Lamborn); (2) "Taking Students Seriously" (A. Gamoran and M. Nystrand); (3) "Higher-Order Thinking and Prospects for Classroom Thoughtfulness" (F. M. Newmann); (4) "Building New Programs for Students at Risk" (G. G. Wehlage and G. A. Smith); (5) "Cultivating Teacher Engagement: Breaking the Iron Law of Social Class" (K. S. Louis and B. Smith); (6) "Putting School in Perspective: The Influence of Family, Peers, Extracurricular Participation, and Part-Time Work on Academic Engagement" (S. D. Lamborn, B. B. Brown, N. S. Mounts, and L. Steinberg); and (7) "Conclusion" (F. M. Newmann). (SLD)