en Environmental Design Environmental Design Research Paper Research Paper Abstract Creating suitable classrooms that can meet the educational needs of mentally-retarded students is vitally important. The present study explores the effect of three physical characteristics of classroom environment on the creativity of educable mentally-retarded children: window view, window size, and classroom size. The participants, one hundred 9-to-11-year-old girl students, took the Test of Creative Thinking-Drawing Production (TCT-DP). The results indicate that natural window view, larger window size (which provides a broader vision), and larger class size positively affected the creativity of the students. The findings of the study can be taken into account in designing psychology-oriented classroom environments that can improve the creativity of students. Classroom Physical Environment, Exceptional students, Creativity, Window View, Window Size, Classroom Size 9 14 http://ijaup.iust.ac.ir/browse.php?a_code=A-11-453-2&slc_lang=en&sid=1 Jamaleddin soheili soheili@qiau.ac.ir 18003194753284600671 18003194753284600671 Yes Kamelia Alimardani kamelia_alimardani@yahoo.com 18003194753284600672 18003194753284600672 No