A study was conducted to determine whether manipulating the classroom environment to be either apprehension producing (AP) or apprehension reducing (AR) could significantly change the level of students' dispositional writing apprehension. Five student teachers and one secondary education supervisor volunteered to participate in the experiment and developed two classroom environments, one AP and one AR. Subjects were 272 students, grades 7-12, enrolled in English classes at cooperating secondary schools. Each student teacher selected two comparable classes in which to implement one AP treatment and one AR treatment, randomly assigned. The treatments lasted 6 weeks and consisted of six writing assignments--one administered per week. In AP classroom environments, students were exposed to high levels of conspicuousness, intense evaluation schemes, continually novel assignments, and ambiguity of directions. In AR classroom environments, students were exposed to low levels of conspicuousness, de-emphasized evaluation schemes, articulation of assignment sequences, and clear directions. Maintenance of treatment was insured through student logs and supervisor observation. Daly and Miller's Writing Apprehension Test, designed to measure dispositional apprehension, was administered to all classes both before and immediately following the treatments. It was hypothesized that posttest scores would indicate significant differences in levels of dispositional writing apprehension between the AP and AR classrooms. Results indicated that classrooms with apprehension-producing environments yielded significantly higher levels of student apprehension than did classrooms with apprehension-reducing environments. (Two tables of data are included and 12 references are attached.) (MG)