The purpose of this study was to explore the influences of text structure on students' conceptual change. Case studies were conducted of three sections of physics (Physical World, Physics, and Honors Physics) for 8 months of an academic year. Qualitative data (including observation field notes, interviews, videotapes, audiotapes, and questionnaires) were analyzed from the perspective of grounded theory by constant comparison through the framework of social constructivism. Results showed that individuals used refutational text to change their alternative conceptions, find support for their scientific preconceptions, gain the language necessary to discuss their ideas, and acquire new concepts. We also found instances, however, when students ignored the text and persisted with their alternative conception, or when students found support for their nonscientific ideas from refutational text. In these cases, we found that either the refutation was not direct enough to be effective, or students' reading strategies were insufficient to facilitate conceptual change. In investigating the power of refutational text, we found that refutational text does cause cognitive conflict. We also discovered that while cognitive conflict may be necessary for conceptual change to occur, it is not sufficient. Although refutational text is effective on the average for groups of students, it will need to be supplemented by discussion for individuals.