Although some research results indicate that joint reflection can improve student-teachers' reflection, it is not clear how the interaction between student-teachers during a joint reflection process helps this to happen. The aim of this paper is to explore how the organisation of joint activity in processes of joint reflection assists students' reflection, by identifying patterns of joint reflection (considering all the participants rather than only tutor-student dyads) and by discussing the functional role of these patterns within the students' processes of reflection and internalisation. Two cases of joint reflection processes between a group of student teachers (15 and 13) and their tutors were examined. In each case, five seminars lasting around one-and-a-half hours each were videotaped and analysed, and individual written reflections after each seminar were gathered and scored. Results showed that joint reflection developed in each case according to different interaction patterns, and that individual written students' reflections improved from seminar 1 to seminar 5 in one of the cases, but not in the others. These results suggest a relationship between interaction patterns of joint reflection and progress in students' individual reflection.