The reviews noted three other important issues in peer assessment:
1. The influence of friendship---It appears from the extensive research evidence available that effective performance probably cause friendship rather than the independent influence of friendship biasing judgments of performance. These results hold up even when peers know that their assessments will affect pay and promotion decisions.
2. The need for cooperation in planning and design---Peer assessment implicitly requires people to consider privileged information about their peers in making their assessments. Thus, they easily can infringe on areas that either will raise havoc with the group or cause resistance to making the assessments. To minimize any such adverse consequences, it is imperative that groups be intimately involved in the planning and design of the peer assessment method to be used.
3. The required length of peer interaction---It appears that the validity of peer nominations for predicting leadership performance develops very early in the life of a group and reaches a plateau after no more than three weeks for intensive groups. Useful validity develops in only a matter of days. Thus, peer nominations possibly could be used in assessment centers to identify managerial talent if the competitive atmosphere of such a context does not induce excessive bias. We hasten to add, however, that in situations where peers do not interact intensively on a daily basis (e.g., life insurance agents), peer ratings are unlikely to be effective predictors for individuals with less than six months’ experience (Mayfield, 1970, 1972).