ABSTRACT
To track a broader spectrum of problems, plus adap tive behaviors, two studies have compared Child Behav ior Checklist (CBCL) and Teacher’s Report Form (TRF) scores for randomly selected children over substantial in tervals. In one study, Achenbach and Howell (1993) found small but significant decreases in American children’s competence scores (effect sizes [ES] 1 to 5%), plus in creases in problem scores (ES 1 to 4%) from 1976 to 1989. TRF scores showed parallel changes from 1981 to 1989 (ES 1 to 2%). In the second study, Dutch children’s CBCLs and TRFs showed no significant changes in Total Problems scores from 1983 to 1993, but did show sig nificant, though small, decreases in competencies and in creases in problems on some scales (ES 1%; Verhulst, van der Ende, & Rietbergen, 1997).
