A study examined the impact of written feedback on goals and self-efficacy, and the impact of goals and self-efficacy on changes in writing performance. Subjects were 137 students in a second-semester freshman-level college English composition class and 5 second-semester graduate assistant teachers. Consistent with social learning theory, results indicated that, among motivational variables, the best predictor of change in writing performance was changes in self-efficacy for writing skills. Among types of written feedback the students received, the best predictor of changes in writing skill self-efficacy was the grades that the students received. Results also indicated that the students entered the semester with limited knowledge about the writing process or their ability, but by the end of the semester, they began to understand the writing skills targeted in an earlier study, and, consequently, their understanding of the writing process, their understanding of their own ability, and their self-efficacy increased. Among the types of written feedback, the best predictor of changes in writing performance was the number of task-specific comments that the students received. In addition, the teachers who gave the most task-specific comments also saw their students' writing scores improve the most. Findings support A. Bandura's (1986) contention that self-efficacy is malleable and positively related to improvements in performance. Findings concerning student goals are more ambiguous. (Contains 63 references, and 21 tables and 14 figures of data. Appendixes present a writing prompt, a scoring rubric, data analysis, directions for coding, and 9 tables of data.) (Author/RS)