This chapter explains the evaluator role "assesses the impact of interventions and follows up on changes made, actions taken, and results achieved in order to provide participants and stakeholders with information about how well interventions are being implemented". Determining such a return is, in part, the role of the evaluator. In short, the evaluator provides feedback to stakeholders about what benefits were received from a performance improvement intervention. Taken together, the role, competencies, and work outputs of the evaluator dramatize the importance of the role for collecting, feeding back, and emphasizing the benefits received from performance improvement interventions. Line managers do have a role to play as evaluators of Human Performance Improvement interventions. Managers and other stakeholders want to know what business needs were satisfied and what return on investment was received from the resources dedicated to performance improvement interventions.