The effectiveness of a Keller and Bloom mastery learning program for high school science students was examined by comparing remediation strategies of both programs and that of a traditional strategy. The data gathered in the experiment in chemistry were from a pre- and post-achievement test. Cognitive achievement was statistically different (p < .025). Additional analysis revealed the greatest difference was between a Bloom and a traditional strategy. Gain score analyses failed to produce any significant differences. A Chi-square analysis of the number of objectives achieved produced significant values of .004 and .034, respectively, for the Keller and Bloom groups over the traditional group. (Author/RH)