Abstract: In this work we analyze peer review experiences of high school students from different schools, working in b-learning activities supported by our Web platform and the educational network called Kelluwen. In this network, students are guided to publish their learning outcomes using Social Web tools with the purpose of enrich collaboration, discussion and co-evaluation with students from other classes in the school network. We report qualitative evaluation of a tool we implemented for facilitating the pairing of reviewers and monitoring of the review process. We also conduct a quantitative evaluation of reviews made by students in 12 different classes. We show that differences exist in the scores and the quality of reviews when comparing reviews made from peers in the same class than when reviewers are from a different class.