In discussing the purpose of evaluation, the guide advises that evaluation strategy and design should be an integral part of the planning process. Among its benefits are to show the need for a specific prevention, enforcement, or public policy strategy; to target programs and material to the appropriate audience; to ascertain whether materials and messages will be effective through pre-testing; and to monitor changes in attitudes, behavior, knowledge, or beliefs among the target audience. When evaluation is an integral part of the planning and implementation process, it includes four stages or types of evaluation: formative, which is most often used to test the appropriateness and effectiveness of project materials; process, which is used to determine whether the project or coalition is working effectively; outcome, which is used to determine the organization's progress toward achieving its goals and objectives; and impact, which may review data on drinking and driving by minors 5 years after an underage drinking prevention program begins and compares that data to a baseline. In addition to descriptions of these types of evaluation, this guide provides examples of when each stage should be used. There are also two methods that can be used: quantitative and qualitative. An appendix provides samples of both of these methods, including a form to be used in counting numbers for quantitative methods and sample interview and focus group questions, as well as a participant observation form for use in qualitative methods. The guide describes the evaluation planning process as well as what to consider in hiring an evaluator. Seventeen annotated resources are listed.