Prescriptive writings on performance evaluation have argued that splitting the administrative (summative) and developmental (formative) roles will lead to evaluatees being less defensive and more open to discussing performance problems and taking suggestions, and that without the responsibility for making an administrative evaluation, evaluators will be able to provide more assistance toward improving performance. These results of splitting the roles should lead to greater improvement in the performance of evaluatees. This article describes the results of a study of splitting the roles between two people. Newly hired teachers in a Midwestern school district were assigned to either a split role group, in which developmental evaluation and feedback were provided by a peer mentor, and administrative evaluation by managers and peer evaluators, or a combined role group, in which developmental evaluation, feedback, and administrative evaluation were provided by a peer. Reactions of evaluatees were assessed using interviews and a survey, and performance ratings and turnover were analyzed. There were no major differences between the groups in terms of openness to discussion of difficulties, reception and acceptance of performance feedback, stress, turnover intentions, actual turnover, or performance improvement. These results suggest that it may be more important to ensure that developmental assistance is provided to evaluatees than to split the evaluation roles.