The purpose of this study was to examine and reflect on two teacher educators' approaches to developing preservice elementary teachers' mathematics assessment literacy. We explored the similarities and differences in preservice teachers' conceptions of good assessment practices and their critique of assessment items. We found that we, as course instructors, had different assumptions pertaining to the role of preservice teachers in the development of assessment and offered different assessment-related course activities. Despite these differences, there were more similarities than differences between the two groups of the preservice teachers with regard to their overall perceptions about good assessment practices and their critique of assessment items. However, we also observed differences in the criteria they used in critiquing assessment items. Discussions and implications are presented in accordance with these findings as a means to improve our own teaching and student learning.