As the number and sophistication of training systems increases, there is a need to evaluate the effectiveness of the systems. The services have attempted to identify and define how that evaluation should be accomplished, primarily by looking at the concept described as "Transfer of Training." This paper identifies the two types of evaluation, formative and summative, that have received universal acceptance in government, industry, and academia. It describes the characteristics of each type of evaluation, and specifies when each should occur. Further, it suggests the role of both the contractor and the government. Those roles include the requirement for active government participation in formative evaluation, a role which has been traditionally ignored. The presentation format of the paper uses a model for evaluation as a foundation for the discussions. The description of the model includes the identification of each requisite step in the process. Each element of the model is amplified in the context of using evaluation for modern training systems.