Drawn from Public/Private Ventures' Notes from a Wind-Down blog, this brief shares some of the organization's closing reflections about evaluation and how it can be used to improve the effectiveness of social programs. In its final year, P/PV engaged in outreach and discussions with partners and experts, and mined its past projects and findings, to identify some of the most pressing questions in three of core areas -- mentoring, out-of-school time, and labor market transitions. This brief compiles the results, with a range of suggested directions for future research, including more work on understanding program costs and improving program practice, further examination of the relationship between program participation and outcomes (especially across programs and settings), and research on the potential of innovative workforce development strategies (like sector-focused training and alternative staffing) to improve the employment prospects of youth and young adults. The brief also presents P/PV's observations about trends in the evaluation of social programs, particularly the rise of "internal" evaluation and what it may mean for efforts to develop more social programs that make a real and lasting difference for young people. Finally, Notes from a Wind-Down shares a few of the most enduring lessons from P/PV's work, which have proved to be relevant for program managers, funders and policymakers alike.