This chapter introduces the reader in the fields of automatic assessment of free-text students’ answers, student modeling and adaptive educational hypermedia. Traditionally, these fields have been studied separately missing the benefits of their synergic combination (i.e., free-text scoring systems which do not keep any student model, and adaptive educational hypermedia systems which do not use any natural language processing technique). In particular, a procedure to automatically generate students’ conceptual models from their answers to a free-text adaptive computer assisted assessment system will be fully described, together with its implementation in the will tools. Furthermore, the authors will explore how useful this new possibility of hybrid learning is both for teachers and students in two case studies carried out during the 2006-2007 and 2007-2008 academic years, in which traditional lessons were combined with the use of the Will Tools both in technical and non-technical domains.
