Responses to a written beliefs test for 178 eighth grade students and interviews with a subset of the students are analysed to investigate students' beliefs about the tentativeness of scientific knowledge and about the autonomy and strategies appropriate for science learning. These three dimensions of beliefs are salient because they align with the image of science teaching promoted by current reform movements. Analyses focus on change in beliefs and relationships among dimensions of beliefs and between those beliefs and students' understandings of science concepts. Results show that students' beliefs do not change much during the one-semester course. Students who view scientific knowledge as tentative also try to understand science. Autonomous students do not hold the most productive learning strategies, though students with low autonomy develop significantly less coherent understandings of science concepts. Instructional implications focus on potential roles of teachers and technology in promoting productive beliefs about scientific knowledge and science learning. Implications for individualized instruction follow classroom-level implications.