The purpose of this chapter is to discuss issues relevant to appropriate and effective evaluation of crime prevention initiatives. A number of topics are addressed. First, the different types of evaluations, or as some would argue the different parts of an effective evaluation, are discussed. The second issue discussed involves theoretical and measurement problems in evaluation. The debate about the appropriate methodology for evaluations forms a core topic in the chapter and helps tie together the different threads raised in the earlier sections. The ultimate goal is to lay a foundation for understanding the importance of evaluation in crime prevention.