This study examined the prediction of reading achievement for 144 second-, third-, and fourth-grade children in classrooms differing in program openness. Intercorrelations of nine cognitive and personality variables were factor analyzed, and four components representing creativity, conceptual tempo, attitude, and intellectuality were extracted. Reading achievement was regressed on these four composite indices plus chronological age, within each of three levels of classroom openness. Comparisons of regression weights indicated that creativity, conceptual tempo, and age decreased in their ability to predict reading achievement, as openness decreased. In contrast, the intellectual factor was increasingly predictive of reading achivement, as openness decreased. (Author)