Several tenets of mastery learning were examined in this study in the context of college level instruction. When students learn for mastery: (1) retention test scores should exhibit small variability and should be unrelated to aptitude; (2) test items which are classified into high and low cognitive behavior subscales should be unrelated to aptitude. The first tenet was partially supported as the relationship between retention and aptitude was uniformly low across three units of instruction, and variability of retention tests was not restricted. No relationship between performance on both high and low cognitive subscales and aptitude was observed. (Author)