This paper examines the theoretical assumptions behind an integrative curriculum model intended to enhance preservice teachers' pedagogical competence for accommodating diversity among school populations. The first section reviews the relevant literature and describes the integrative multicultural model for preservice teachers. The next two sections present two research studies which test the impact of this curriculum model. The first study, "Stability and Change in Preservice Teachers' Value Dispositions for Teaching Culturally Diverse Students," examines change in preservice teachers' dispositions about cultural diversity in school settings in relation to personal knowledge and values. Excerpts of preservice teachers' analyses of diversity in school settings suggest that cultural knowledge was highly valued for effective teaching among these teachers. Results indicate that the acquisition of knowledge of diversity among student populations requires some direct experiences in school settings. The second study, "Value of Expectancy and Achievement in Shaping Student Teachers' Competence for Accommodating Diversity among Student Populations," examines diversity among student teachers, cooperating teachers, and college-based supervisors' expectations and perceptions of achievement for the student teaching internship. As anticipated, student teachers' expectations and perceptions of achievement in practice teaching were significantly different from those of their cooperating teachers and college-based supervisors. This study also examines the nature of the teacher education program for enabling prospective teachers to accommodate diversity in P-12 schools. (Contains 91 references.) (ND)