Evaluation professionals can benefit from practice in the same way that lawyers, doctors, and other professionals improve their performance through practice. The case method enables practice through role plays and situational analyses. Cases provide openings for evaluators and program planners to experiment with new norms of communication regarding what are perceived as positive and negative comments. Cases are one way to help program planners confront what Lovallo and Kahneman (2003) call "pertinent outside-view information." Thus, cases can help evaluation staff and program planners overcome the three cognitive biases that contribute to delusional optimism: (1) Anchoring; (2) Competitor neglect; and (3) Exaggeration of abilities and control. The evaluation cases in Chapters Two through Four in this issue of "New Directions for Evaluation" ["Evaluation of the Fighting Back Initiative" (Sherwood, EJ791776); "Evaluation of the Central Valley Partnership of the James Irvine Foundation" (Campbell, Patton, & Patrizi, EJ791775); and "Evaluating Home Visitation: A Case Study of Evaluation at the David and Lucile Packard Foundation" (Sherwood, EJ791779)] provide compelling opportunities for role playing and simulations among evaluation professionals and their colleagues.