This paper examines the conditions which supported the use by pre-service teachers' of a shared database to enhance the development of a mathematical knowledge-building 'community'. We focus on a cohort of 100 students enrolled in the 4th year of the BEd(Primary) program at QUT. The aspects of the learning environment designed to promote a sense of community comprised the following elements: small group discussions in which participants worked on measurement workshops as well as access to shared electronic databases which included conferences of commentary on mathematics to which pre-service teachers, their lecturers and researchers could post ideas and comments. Examined in this paper are the conditions, practical, social and cognitive, under which progressive discourse (Bereiter,1994) emerged from these discussions. Progressive discourse here is being taken to mean advances in understanding through engagement and knowledge building.