In the Computer Supported Collaborative Learning (CSCL) research field a lot of attention has been devoted to the use of either collaborative techniques, or “patterns” or “scripts”, which are all instruments able to provide – at different levels of granularity - guidance to students and a structure to the online collaborative activity (Kanuka & Anderson, 1999; Dillenbourg 2002; Hernández-Leo et al., 2005; Jaques & Salmon, 2007; Persico et al., 2008; Fischer et al., 2009; Pozzi & Persico, 2011).

A collaborative technique (i.e. Discussion, Peer Review, Role Play, Jigsaw, Case Study, etc.) can be defined as a structured content-independent path, usually, which serves to scaffold a learning activity (which on the other hand are content dependent). A technique usually specifies the phase repartition and timing of the learning activity; the nature of the task to be performed and the work distribution among learners and groups; the social structure of the group(s) (in terms of size, composition, etc.); the mode of interaction among participants and groups (Persico & Pozzi, 2006).
Among other collaborative techniques, Peer Review is being increasingly appreciated as a useful technique especially in higher education and in lifelong learning contexts, because of its ability to “model real world professional activities, providing learners the opportunity to learn how to deal with criticism and how to provide constructive criticism to others” (Anewalt, 2005).

In this paper a pilot study is described, which focuses on the use of the Peer Review as a technique to structure collaboration during a CSCL activity. The dynamics and interactions raised by the Peer Review in the experimental context are analysed and evaluated using a mixed approach, based on the quantitative and qualitative analysis of the messages exchanged among the students during the activity itself. The aim of the study is to understand the impact of the proposed technique on the online learning process, and to investigate whether different social structures adopted during the activity lead to any difference in the resulting interactions and learning process.