To maximize our teacher candidates' learning about culturally and linguistically diverse students, we developed and implemented "Case-Based Instructional (CBI) Modules" (Language, Identity, Family, Assumptions) in two teacher preparation courses at a US university. We examined the "Modules'" impacts on teacher candidates' learning, self-efficacy, attitudes, and transfer of learning to novel contexts. Examining the Modules' effectiveness within and across two delivery modes indicated that both "instructor-facilitated" and "instructor-supported" approaches to CBI elicit similar positive attitudes and are effective in enhancing teacher candidates' learning, but not transfer. When teacher candidates' analyses of cases were not facilitated by instructor, however, there were some missed opportunities for learning.