A study was undertaken to evaluate how a mastery approach to teaching history on the high school level influenced student achievement and attitudes. Mastery learning is interpreted to include assumptions regarding student learning capability as well as specified curricular/instructional/evaluative procedures. Essential to mastery learning strategy are feedback corrective procedures such as diagnostic tests. Participants in the study included 69 high school students assigned to three sections of United States history. The sections were based respectively on highly specific formative tests plus learning correctives, relatively general formative tests and learning correctives, and relatively general formative tests with no learning correctives. An objective test measured student cognitive mastery of unit material and a questionnaire measured student attitudes toward the unit. Tests and questionnaires were statistically analyzed. Findings indicated that there was a significant difference among the three treatment groups and that the group exposed to highly specific formative tests and learning corrections outperformed the other two treatment groups. The conclusion is that a combined feedback-corrective strategy in social studies instruction can improve student achievement and result in more favorable unit evaluations. (DB)