Previous funding from NSF to this group has led to the development of a book of lessons for dealing with preconceptions in mechanics that has shown very promising results in classroom trials. Using these lessons as a starting point, this project will develop a set of instructional strategies for fostering meaningful learning and conceptual change in science. The project will: (1) conduct studies of conceptual in pairs of students learning science; (2) conduct studies of conceptual change in experts; (3) form these studies develop more detailed theories of conceptual change processes; (4) develop an accompanying set of effective instructional strategies. These strategies can be used by teachers and curriculum developers to promote student literacy in science and widen the population that has access to fundamental science concepts. Thus, the project in aimed at giving students broader access to powerful scientific ideas.