Adele Wolfson, Professor of Chemistry, discusses how in-depth interviews with students reveal information about their understanding of scientific concepts and their ability to integrate knowledge across disciplines. She presents results from two studies. One, from the NECASL longitudinal study of students at liberal arts colleges, examined the experiences of science majors, their pattern of enrollment, and connection of science to non-science courses. The second project explored concepts about energy transformations and the extent to which students are able to transfer knowledge from general chemistry into biochemistry. Both projects have implications for the ways we teach and the ways we organize the curriculum.