A 20-week classroom-based study was conducted to investigate the extent to which a computerized learning environment could facilitate students' development of higher-level thinking skills associated with scientific inquiry. In two classes students' interactions with a scientific data base—Birds of Antarctica—were closely monitored, and the mediating roles of the teachers' epistemologies were examined. Interpretive data were generated and analyzed in relation to a constructivist perspective on learning. In the class where the teacher implemented a constructivist-oriented pedagogy, students took advantage of enhanced opportunities to generate creative questions and conduct complex scientific investigations. These higher-level thinking skills were much less evident in the class in which a more transmissionist-oriented pedagogy prevailed. The results of the study suggest that it is not the computer itself that facilitates inquiry learning; the teacher's epistemology is a key mediating influence on students' use of the computer as a tool of scientific inquiry.