Implementation matters: a review of research on the influence of implementation on program outcomes and the factors affecting implementation.

The first purpose of this review was to assess the impact of implementation on program outcomes, and the second purpose was to identify factors affecting the implementation process. Results from over quantitative 500 studies offered strong empirical support to the conclusion that the level of implementation affects the outcomes obtained in promotion and prevention programs. Findings from 81 additional reports indicate there are at least 23 contextual factors that influence implementation.

Effects of positive youth development programs on school, family, and community systems.

A review of efforts at social system change in 526 universal competence-promotion outcome studies indicated that 64% of the interventions attempted some type of microsystemic or mesosystemic change involving schools, families, or community-based organizations in an attempt to foster developmental competencies in children and adolescents. Only 24% of the reports provided quantitative data on the change that occurred in targeted systems. However, studies containing the necessary information produced several mean effect sizes that were statistically significant, and ranged from modest to large in magnitude.