A study elaborated on the results of previous research on the effectiveness of the R-WISE (Reading and Writing in a Supportive Environment) software by examining the effects of the student factor of learner-control and the environmental factor of the teacher's preferred instructional style on student writing performance. R-WISE includes 3 specific exercises that teach key pre-writing, drafting, and revision skills identified as deficient in novice writers. Subjects were 1,276 public high school students from the classes of 32 teachers. Two data collection instruments were used: a writing sample used for pre- and posttesting, and an instructional styles inventory. Results indicated a small but statistically significant effect of both the level of learner control and the teacher's preferred instructional style on learning outcomes. Results also showed a small interaction between student and environmental factors. Findings support learner control research and suggest an increase in the adaptability of R-WISE to accommodate variable levels of learner-control, and preferred instructional styles of the teachers. (Contains 13 references; 3 tables and 5 figures of data; and 3 computer screens from the R-WISE software.) (Author/RS)