One important feature of vocational education is to provide students with solid conceptual knowledge along with substantial practical experience, acquired in school and workplace contexts, respectively. However, the research provided evidence that students do not spontaneously articulate the knowledge acquired in different contexts, and that specific instructional activities have to be designed and introduced. The present study deals with this type of activity conducted in a vocational school for health and social care assistants, which involved the use of collaborative writing about workplace critical incidents. The goal was to identify the patterns of interactions, and specifically the type of peer-feedback that engage students in productive collaboration. Qualitative analyses show that the writing productions could be categorized in four collaboration patterns differing in the level in which students would elaborate on their peers' experience and profit from the peers' suggestions in order to improve their understanding. On this basis, we propose a series of recommendations for implementing effective and instructionally relevant collaborative writing activities in vocational education.