Strategies described in the book are partially derived from two formal studies, conducted from 1982 to 1990 on school campuses in Los Angeles. Data supports the notion that effective strategies emphasize positive, proactive, cooperative and preventative approaches. Additional data has been obtained from current literature and research, from interviews with former and present gang members, from discussions with school officials and from continuing and informal study of gangs. Although not a study, history or sociology of gangs, this book is an excellent starting place for learning more about gangs.