In this paper, we report a research study concerning the use of online e-learning platform for enhancing formative assessment strategies through which the students are asked to provide feedback on their peers’ productions and are therefore activated as instructional resources for one another. In playing the assessor role, students are prompted in developing continuous reflections on their learning processes. The activity has been experimented at undergraduate level in two different Universities in Italy, with courses with different mathematical contents. We describe the design of the activity and analyse the first experimental results.