A major focus of research on teaching and learning for the past decade has been directed toward developing an understanding of student behaviors and thought processes related to achievement. Using a mediational-processes approach, researchers have identified engagement variables that predict skill learning gains, most notably the quality and quantity of practice and student self-perceptions of efficacy and competence. We sought to extend this correlational research by examining how one aspect of instruction, task progressions, influenced students’ practice quality and task-related cognition. University students enrolled in tennis classes were taught and practiced the serve under one of three conditions, two characterized by easy-to-difficult task sequences, and the third involving practice of the criterion task. Data were collected on students’ practice trials and three task-related cognitions: motivation, self-efficacy, and perception of success. The results indicated student practice and task-related thoughts varied according to entry skill level and the condition under which they practiced. Instructional conditions involving easy-to-difficult progressions resulted in more successful and appropriate practice trials and enhanced student self-efficacy and motivation. These findings parallel those previously reported on the impact of student ability on practice quality and add to an understanding of how instructional conditions affect what students think and do in physical education class contexts.