Although many program managers look to data to inform decision-making and manage their programs, high-quality program data may not always be available. Yet such data are necessary for effective program implementation. The use of high-quality data facilitates program management, reduces reliance on anecdotal information, and ensures that data are available for decision-making purposes. Both research and program experience have shown that decision-support data systems are effective tools for gathering high-quality data. In an effort to expand what is known about decision-support data systems, Child Trends conducted a review of research on this topic. Child Trends also collected data on decision-support data systems as part of a study on the role of organization-level activities in the effective implementation of out-of-school time programs. This brief presents findings from that study and the research review and links these findings to effective strategies for using decision-support data systems in out-of-school time programs. (Contains 1 footnote.) [For Part 5, see ED510680.]