Despite the ubiquity of the term "inquiry" in science education literature, little is known about how teachers conceptualize inquiry, how these conceptions are formed and reinforced, how they relate to work done by scientists, and if these ideas about inquiry are translated into classroom practice. This is a multicase study in which 14 preservice secondary science teachers developed their own empirical investigations--from formulating questions to defending results in front of peers. Findings indicate that participants shared a tacit framework of what it means to "do science" which shaped their investigations and influenced reflections on their inquiries. Some facets of the participants' shared model were congruent with authentic inquiry; however, the most consistent assumptions were misrepresentations of fundamental aspects of science: for example, that a hypothesis functions as a guess about an outcome, but is not necessarily part of a larger explanatory system; that background knowledge may be used to provide ideas about what to study, but this knowledge is not in the form of a theory or other model; and that theory is an optional tool one might use at the end of a study to help explain results. These ideas appear consistent with a "folk theory" of doing science that is promoted subtly, but pervasively, in textbooks, through the media, and by members of the science education community themselves. Finally, although all participants held degrees in science, the participants who eventually used inquiry in their own classrooms were those who had significant research experiences in careers or postsecondary study and greater science-content background.