A model of conceptual change in physics was tested on introductory-level, college physics students. Structural equation modeling was used to test hypothesized relationships among variables linked to conceptual change in physics including an approach goal orientation, need for cognition, motivation, and course grade. Conceptual change in physics was determined using gains from pre- to post-administration of the Force Concept Inventory (FCI). Results indicated that need for cognition and approach goals had a significant influence on motivation. Motivation influenced change scores on the FCI both directly, and indirectly, through course grade. Finally, course grade directly influenced conceptual change. The implications of these findings for future research and developing students' conceptual change in physics are discussed. (Contains 2 figures, 2 tables, and 1 note.)