We present an empirically based model for modeling the quality of pre-service teacher reflection. Conversations from twelve groups of a total of 47 pre-service teachers were video recorded and transcribed verbatim. First, we analyzed their conversations through practical epistemology analysis and an operationalization of Dewey's definition of reflection to identify the moments of reflection that appeared in the pre-service teachers' talk. Thereafter, we employed Dewey's reflective attitudes, responsibility, open-mindedness and whole-heartedness, with the aim of understanding their roles in moments of reflection and how they relate to the quality of reflection. Our results show that the reflective attitudes played different roles and based on these roles and on particular patterns of the attitudes in our data it was possible to use them for modeling the quality of the pre-service teachers' reflection. We suggest that presence of all of the attitudes corresponds to higher quality than absence of any of them. Moreover, identifying absence of one or more attitudes in PSTs' reflection makes it possible to explicitly talk about what aspects of the reflection that should be improved, and why. Our results contribute with a first tentative model which may support teacher educators work with the development of pre-service teachers' reflective practice.