Adaptation techniques can be applied not only to the multimedia contents or navigational possibilities of a course, but also to the assessment. In order to facilitate the authoring of adaptive free-text assessment and its integration within adaptive web-based courses, Adaptive Hypermedia techniques and Free-text Computer Assisted Assessment are combined in what could be called Adaptive Computer Assisted Assessment of Free-text Answers. This paper focuses on the integration of this type of assessment within adaptive courses, as well as on the presentation of an authoring tool able to manage the insertion and modification of different question statements and reference answers for open-ended questions. The results of the evaluation of this tool with course authors show the feasibility of proposing and evaluating open-ended questions adapted to each student, as well as that of getting a better model of the student's progress. (Contains 1 table and 8 figures.)