An interactive multimedia tutoring system has been designed to help tertiary students achieve deep understanding of fundamental ideas underpinning major aspects of science. This system assists students to align their personal theories with scientific theory and thus to be less dependent upon memorisation. Students are guided to recognise their personal theories and then are challenged to contrast their explaining power with scientific ideas. Learning barriers arising from, first, the inhibiting power of students' intuitive ideas and, secondly, the uneasiness brought about by a discourse in formal logic in the vulnerable, early stages of learning are confronted. This computer-mediated learning package, itself based on research into personal theories, analogy generation, the role of concrete reasoning and conversational methodology, now suggests a research agenda inquiring into learning media by provoking questions about existing and possible learning strategies and their evaluation.