This dissertation explores teacher and paraeducator training with a specific focus on generalization of training outcomes and social validity. Chapter 1 presents brief background information to introduce the research questions posed in Chapters 2, 3, and 4. Chapter 2 presents a systematic literature review of educator training studies that measured generalization of educator training outcomes. Chapter 3 presents a multiple method research study that evaluated the effect of a paraeducator training package that consisted of initial training and teacher-delivered coaching with performance feedback on paraeducator generalization. Chapter 4 presents the results of a secondary data analysis of the National Teacher and Principal Survey (NTPS) that focused on professional development opportunities available for teachers in the United States. Finally, Chapter 5 provides a research statement that discusses the place of this dissertation in my work and future directions for my research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]