Combining intervention diffusion with change in clinical practice and public policy is an ambitious agenda. The impressive effort in Hawaii can be instructive, highlighting questions for a science of treatment dissemination. Among these questions, some of the most important are the following: (a) Who should be targeted for change? (e.g., "downstream" clinicians in practice, "upstream" clinicians in training, consumers, "brokers," policy makers, or payers?); (b) What should be disseminated? (e.g., full evidence-based protocols, specific treatment elements or "kernels"?); and (c) Which procedures maximize change? (e.g., what combination and duration of teaching, supervision, consultation, and other support?). Ultimately, change efforts need to assess what aspects of practice were actually altered, what measurable impact the changes had on clinical outcomes, and what changes in practices and outcomes can be sustained over time.