The effects of 9 assessor characteristics on scores given by 49 assessors to 111 assessees in 3 police and 6 fire service assessment centers for local governments were investigated. Assessors included those who had and who did not have experience in the job under consideration, and who differed on several other characteristics, including the following: age, race, gender, previous assessment center experience, education, managerial experience, assessor managerial level, and tenure in that position. Age and the rank of the assessor were the only characteristics that had a significant effect on the scores. However, the magnitude of the effect was quite small (less than two percent of the variance was explained by these two factors). The results might be attributed to the process used to select the assessors, the way the centers were conducted, and the type and intensity of assessor training. The study concluded that assessor characteristics were minor factors in the overall scoring model. Reasons for this independence of scores from assessor characteristics may have included the following: (1) the model used for selecting the assessors, (2) the training provided for the assessors, (3) the use of highly exercise-specific behaviorally anchored rating forms, and (4) the use of an integrating discussion technique after each exercise in eight of the nine centers. (The report includes an appendix that lists criteria for selecting assessors). (Contains 15 references.) (Author/KC)