The purpose of this study is to analyze differences in risk factors and determinants of injuries and other health related behaviors for early-- to mid-adolescent age groups across the majority of developed countrIes. A representative U.S. school-based sample of adolescents at average ages of 11.5, 13.5, and 15.5 years is needed to participate in the international study. The contractor is needed to participate in the international study. The contractor shall use a questionnaire standardized to conform to the protocol of the World Health Organization (WHO) study on Health Behaviors in School Children (HBSC) for the U.S. The school-based survey shall provide estimates at the 95% confidence level for total U.S. students and at the 90% confidence level for the minority oversamples. The resulting data shall be used to improve the quality of health promotion programs for youth.