Assessment is indissociable of learning activities led by teachers or performed by pupils. For a long time and in various disciplines (didactic, educational sciences, psychology, docimology), assessment is the topic of several works and reflexions which contribute to define it and to specify the nature of the supports activities which allow to implement it. Generally, assessment regulates learning activities and check pupils competences. But assessment also takes part in the pupils' selection and in their social integration with examinations and contests. The choice of the methods, the tools and the techniques depends mainly on the objectives assigned by the teaching.