This study examined various influences on special education preservice teachers' appropriation of pedagogical tools for teaching reading to students with high-incidence disabilities using an activity theory framework. Interview, observation, and artifact data were collected on 6 preservice teachers, their reading methods course instructors, field supervisors, and practicum cooperating teachers. Using grounded theory methods, 4 concepts emerged as chief influences on participants' appropriation of conceptual and practical reading tools: (a) opportunities to appropriate knowledge in practice, (b) personal qualities, (c) motivation for knowledge assimilation, and (d) access to knowledge. Specific information related to these 4 concepts and their relationships are reported with implications for future research and practice in special education teacher education. (Contains 3 tables and 1 figure.)