In this paper we propose a framework for modeling, representing populating and enriching information from online collaborative sessions within Web forums. The main piece of the framework is an ontology called Collaborative Session Conceptual Schema (CS 2) that allows for specifying collaborative sessions. The paper describes the information this ontology needs to know, the alignment of the ontology with the ontologies of relevant specifications, how the ontology can be automatically populated from the data existent in forums, and how to model such data about what is happening during the collaboration by using a dialogue-based model. This model is based on primitive exchange moves found in any forum posts, which are then categorized at different description levels with the aim to effectively collect and classify the type and intention of the forum posts. An experiment has been conducted to assess the validity and usefulness of the presented approach. The research reported in this paper is currently undertaken within a FP7 European project called ALICE.