A study of one grade cohort of students taught in a Chicago Mastery Learning Reading (CMLR) Program was extended to two additional cohorts, one older and one younger than the original group but who were taught using the same method. The students' reading comprehension test scores were compared with those of students in other schools, not taught by the CMLR method. The findings were similar to those for the original group, showing the younger students' performance to be slightly lower than the control group's and the older students' to be higher than national, regional, and control group norms. The apparent inconsistency of program results across years suggests that any CMLR program impact should be looked for by other means. (MSE)