The HRY demonstration has provided strong support for local and cross-site evaluation and plans to incorporate evaluation results into demonstration policy to encourage stronger local evaluation, more coherent program planning and management, use of the risk and resiliency approach to program design, and more comprehensive program purposes and activities. In April 1995, the Division of Knowledge Development and Evaluation within CSAP initiated the third cross-site evaluation of HRY programs using a clear conceptual framework that emphasized the risk and resiliency approach used by HRY grantees funded in 1994 and 1995. A quasiexperimental design used for 48 sites involved about 6,000 treatment and 4,000 comparison subjects. A common questionnaire was used at all sites to generate data that would support a flexible, regression-based analysis plan. In addition to contributing to the systematic development of substance abuse prevention knowledge, the CSAP cross-site evaluation of HRY programs was intended to advance understanding of the design, implementation, and use of large multisite evaluations as sources of policy learning. Evaluation results were not yet available when the article was written, but data collection and analysis procedures and barriers to cross-site evaluation are described. 21 references, 2 tables, and 1 figure