Although family support has gained widespread acceptance as a viable human-service delivery approach, particular characteristics of family support models often present challenges to determining clear program outcomes. Family support models have emerged from a variety of theoretical and nontheoretical approaches, reflected in the wide array of service mechanisms and diverse perspectives on the scope, content, and effects of programs. The absence of a clear empirical foundation on which to base decisions has led to confusion among developers and evaluators about which aspects of these programs to assess.