This paper presents the REASONING, the third module of a computerized system (AUXILIAR), designed to help human-tutors redefine information for those students who have difficulties in grasping deployed educational topics. To this end, there is an intelligent mechanism that facilitates the assessment process and searches for similar cases produced by other students in past situations. This search enables the system to redefine the information content to be rendered to the student in order to eliminate deficiencies detected during a formative assessment without considerable intervention by the tutor. To reach these goals, concepts of Artificial Intelligence (Case-based Reasoning, more specifically) and man-machine interaction are exploited. Thereby, there are presented the format of a Case, the structure of the Case Library, as well as the intelligent retrieval mechanism that was developed.