This study establishes the types of teaching experiences that graduate students have in graduate school, their teaching approach, and how these affect teaching efficacy. Data were collected from 327 graduate students from a variety of degree program disciplines at various stages in their degree programs. A sources of teaching efficacy questionnaire was developed using confirmatory factor analysis and exploratory factor analysis. Hierarchical multiple regression was used to determine if a significant amount of variance in teaching efficacy could be explained by the sources of teaching efficacy reported by graduate students. A series of regression analyses was used to determine if a significant amount of variance in teaching efficacy could be explained by the teaching approach. Hierarchical multiple regression was then used to determine if a significant amount of variance in teaching efficacy could be explained by the sources of teaching efficacy and teaching approach, combined. Positive affective states and positive verbal experiences contributed significantly to teaching efficacy. Conceptual change/student focused approaches, for both lecture and discussion class styles, contributed significantly to teaching efficacy. Positive affective states and conceptual change/student-focused (lecture) significantly influenced teaching efficacy in the combined model. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]