Problematic issues in developing preservice teachers' capacities for reflection include: distinguishing reflective thinking from reflective action; immediate versus extended time frames for reflection; the complexity of critical reflection and the need to foster it over a considerable period; and the role of problem solving in reflection. An ongoing investigation into reflection is being undertaken within the Secondary Bachelor of Education course at the University of Sydney (Australia), based on student reports and self-evaluations, videotapes of their teaching, and interviews. Analysis demonstrated clear evidence of student teachers undertaking reflection in their final year, with the largest proportion of reflective units in written reports being descriptive reflection rather than critical or dialogic reflection. Barriers that hinder reflective approaches are identified. A framework for conceptualizing and researching reflection within the context of professional preparation is proposed. Components of the developmental framework include: technical reflection, where skills are evaluated in controlled or simulated situations and immediate feedback is provided; reflection-on-action, with its three forms being descriptive, dialogic, and critical; and then reflection-in-action, based on contextualization of multiple viewpoints. An appendix lists criteria for the recognition of evidence for different types of reflective writing. (Contains approximately 70 references.) (JDD)