This report presents findings of a three-year study to examine how preservice teachers develop an awareness of the needs of academically diverse learners, including gifted students, and implement and/or modify instruction to meet those needs. Preservice teachers were assigned to one of two treatment groups: either participation in an interactive full-day workshop on differentiation (n=22) or participation in the workshop and work with a curriculum coach during student teaching (n=23). Both groups and a comparison group who received neither treatment were followed through their first year assignments as regular class teachers. Qualitative analysis revealed several themes: (1) preservice teachers used ambiguous criteria for identifying student differences and needs; (2) preservice teachers expressed limited knowledge concerning differentiating instruction and demonstrated limited strategies for differentiation; (3) preservice teachers were influenced by factors, such as the structure of the school curriculum, which complicated and discouraged understanding and addressing student differences and needs; (4) participants in both intervention groups expressed a consistent concern with differentiation as part of their teaching goals and the intervention provided a starting point for changing practice. The curriculum coach was most effective when the coaching was compatible with the practices of the cooperating teacher or the university supervisor. Contains approximately 150 references. (Db).