During the 1976-77 academic year the Ganado (Arizona) Title VII Bilingual Education Project operated within a Cooperative Teaching Model based on language roles. Each teacher was assigned a role based on language responsibility: English language teachers concentrated on teaching English as a second language, while Navajo language teachers taught cognitive skills in Navajo, including initial literacy, science, social studies, and math. The model operated on a departmentalized-homeroom basis; during the morning children rotated from subject to subject and in the afternoon they remained in their homeroom where the teaching reinforced concepts taught during the morning. The program involved 5 kindergarten classrooms (114 students) and 6 first grade classrooms (137 students). Assessment of in-service staff training and development, parent involvement, materials development, objectives and goals, and student progress led to the following conclusions: good progress in student achievement was evidenced in all areas of the curriculum; the areas of greatest achievement were in Navajo social studies and the development of oral English language production, and standardized English achievement tests were inappropriate to evaluate student achievement in a Navajo language curriculum. Recommendations called for program refunding, expansion to the second grade, delaying introduction of English reading until the second grade, and review of the overall instruction model. (NEC)