This article presents ASKER, a tool for teachers to create and disseminate self-assessment exercises for their students. Currently used in the first year of a bachelor's degree at the University of Lyon (France), it enables students to carry out exercises in order to evaluate their acquisition of concepts considered important by the teacher. ASKER enables the creation of exercises (matching, grouping, short open-ended questions, multiple choice questions) that can be used to assess learning in many different fields. To create exercises to assess a concept, the teacher defines a model of exercises that will enable the generation of various exercises, using text or image resources. Such an exercise model is based on constraints that the exercises created from this model must comply with. Automatic generators create, from the resources defined by the teacher, many exercises respecting these constraints. The possibility for the learner to request the generation of several exercises from the same model enables her to assess herself several times on the same concept, without the teacher having to repeatedly define many exercises.