At most Danish universities dramatic changes of the natural science programmes are under way. These changes are carried out both in response to external forces, and to internal ones, such as the need to rethink curriculum and pedagogy. But while the answer - structural reforms - is clear, the major questions remain open: What is the aim of modern natural science education? How can the teaching methods and curriculum structure best support all this? How are changes of teaching practices best initiated? How does the university teacher improve his or her own teaching? These questions were addressed at the third May Conference of the Centre for Educational Development in University Science (Dansk Center for Naturvidenskabsdidaktik, DCN), 22 -23 May, 2003, in Korsør, Denmark. This publication contains presentations given at the conference by keynote speakers. Further, it includes extensive reports from the four conference workshops and from the concluding panel debate.