In this paper, we present an automatic procedure to generate students? knowledge conceptual models from their answers to an automatic free-text scoring system. The conceptual model is defined as a simplified representation of the concepts and relationships among them that each student keeps in his or her mind about an area of knowledge. It is considered that each area of knowledge comprises several topics and each topic several concepts. Each concept can be identified by a term that the students should use. A concept can belong to one topic or to several topics. The conceptual model is graphically displayed to the teachers as a conceptual map so that they can instantly see which concepts have already been assimilated and which ones should still be reviewed as they have been misunderstood.