Identifying victims of peer aggression from early to middle childhood: analysis of cross-informant data for concordance, estimation of relational adjustment, prevalence of victimization, and characteristics of identified victims.

Two studies were conducted to investigate cross-informant measures of children's peer victimization. In Study 1, self- and peer reports of victimization were compared for 197 children from Kindergarten (M age = 5.73) to Grade 4. Before Grade 2, peer reports were less reliable than self-reports and were poor estimators of relational adjustment. In Study 2, single- versus multiple-informant (self, peer, teacher, parent) victimization measures were compared for 392 children across grades 2 (M age = 8.73) to 4. Results indicated that (a) data from the four informants were reliable and increasingly concordant over time, (b) no single-informant measure proved to be the best predictor of relational adjustment, and (c) a multi-informant composite measure yielded better estimates of relational adjustment than any single-informant measure.