This study is concerned with analyzing the effects of classroom environment on students' achievement and perceptions of their learning environment. The learning environment was analyzed from the perspectives of teachers, students, and principals. The sample included one class from each of 25 elementary schools, including architecturally open schools as well as schools of conventional architectural design. Student subjects were enrolled in second, third and fourth grades. The Open Education Teacher Questionnaire (OETQ) was used to establish criteria for openness. The total openness scores of teachers and principals on the OETQ were used to separate sample schools into three groups: traditional, medium open, and high open. Scholastic achievement and student perception of the learning environment were measured by the Metropolitan Achievement Test (MAT) and My Class Inventory (MCI), respectively. Teacher and principal scores on the OETQ, as well as pupil data, were analyzed by using both univariate and multivariate statistical techniques. Data from white pupils and black pupils were analyzed separately. A number of findings are discussed and data tables are included. (Author/MS)