A study of a single-sex learning environment was conducted in a public school, Edward Hand Middle School in Lancaster, Pennsylvania; sixth, seventh, and eighth grade students were grouped homogeneously by sex for all major subjects for a period of one semester and grouped heterogeneously for one semester. The study examined the effects that the single-sex learning environment had upon students' academic achievement and attitudes toward learning and behavior, according to student and teacher perceptions. Teachers' and students' perceptions of the single-sex environment at Edward Hand were studied as part of a graduate course in research methods in education. Data were gathered through a student survey and a teacher survey designed by the students in the graduate education course. Participants at Edward Hand originally included 80 students and 10 teachers, but because of the transient student population, only 35 students were available to be surveyed. Survey responses were analyzed with a non-parametric chi-square goodness of fit. Of the six questions for students, statistically significant results were obtained for three questions. On the teacher surveys, statistically significant results occurred on four of the seven questions. Results indicated that teachers and students perceive that single sex classrooms have educational benefits, such as improvements in self esteem, discipline, and academic growth for both male and female students. Contains 29 references. (BT)