This study investigated the ways in which beliefs about the nature of the science vary as a function of an individual's chemistry expertise and chemistry research experience across the range from high-schools students, whose exposure to chemistry occurs in the classroom, to practicing research chemists. Interviews conducted with a total of 91 participants probed three key research questions: Do the participants' epistemic beliefs vary as a function of chemistry expertise? Are there discipline-specific values and heuristics that guide chemistry research? How does research experience influence participants' epistemic beliefs? We found that participants' epistemic beliefs varied significantly with chemistry expertise and with exposure to authentic research in chemistry. Differences in both the duration and the nature of participation in research had a significant effect on how participants conceptualized science and scientific research. We noted that only the practicing scientists saw a productive role for empirical anomalies that arise in the course of doing research. We found that research chemists thought about their scientific work in terms of a building or "engineering" model of science, rather than the classic hypothetico-deductive model of science invoked by some science educators. We concluded that current characterizations of the nature of science in science education may underrepresent important discipline-specific aspects of science. These results are discussed in terms of implications for science education.