This study was concerned with implementing guidelines from studies of the differences between boys and girls in school-related behaviors to test the contribution made to educational goals by considering gender of the learner. The basic strategy was to consider tested sex differences in behavior and to use these as a basis for developing classroom activities and materials most appropriate for boys. Section 1 of the report contains a review of studies of school-related behaviors and abilities of boys and a discussion of school innovations which can help to accommodate sex differences. Section 2 describes the experimental classroom program tested in this study. Included in this description are: (1) the goals, physical organization, and equipment of the classroom, (2) organization of the classroom day, (3) examples of curricular modifications, (4) a sample curriculum unit, (5) classroom materials, (6) classroom stations, and (7) pupils' comments. Section 3 presents the design, methods, results, and conclusions of the program evaluation. A list of suppliers of the classroom materials used in the study is included. (JMB)