This report's central theoretical assumption is that adolescents are in risk of problem behavior if they are not sufficiently equipped with the social and psychological competencies to cope with culturally and socially defined developmental tasks specific to their ages. The first chapter describes the socio-structural factors which have changed the phase of adolescence during the last 30 years in West Germany. Special emphasis is given to the continued extension of the time spent at school and the growing tendency to postpone employment within the life course. The second chapter reports the findings of case studies which analyze the biographic importance of school-time for individual life courses during adolescence. A qualitative longitudinal study over 7 years is presented in which research was undertaken into how 40 adolescents aged 14 to 21 perceived the social and structural changes in their living conditions, in particular their educational and vocational opportunities, and how they ranked their school-time in relation to their individual biographies. Findings are discussed which revealed that school was primarily judged to be of instrumental value for acquiring the marks of adult status. The third chapter examines the role of school in the social support network of adolescence. A survey study of 2,000 students aged 14 to 21, designed as a 5-year longitudinal study starting in 1986, is described as a follow-up to the case studies which will examine school-related problems and the potentials for intervention that school systems can offer to adolescents. It is explained that the survey study will evaluate programs for social work and integrated youth services in school. (Author/NB)