The overall purpose of this study was to investigate the role of personal relevance in conceptual change. First, we used an experimental design to investigate the role of augmented activation--which directly implicated teachers' personal prior beliefs about mathematics learning and instruction--and refutational text manipulations on short and long-term conceptual change in preservice and inservice teachers' constructivist beliefs about mathematics to test for a mechanism of change. Second, we examined the relationships among affect, cognitive processing, and conceptual change to clarify our understanding of the mechanisms of the conceptual change process and to empirically test key hypotheses in the Cognitive-Affective Model of Conceptual Change (CAMCC). Our results indicated that messages that heighten the personal relevance and challenge to prior beliefs with contrary evidence (i.e., augmented activation) produced conceptual change in preservice and inservice teachers' mathematics beliefs, whereas there was no consistent effect of refutational text. We also found support for several key pathways in the CAMCC, with implications for conceptual change theory and teacher education.