In order to give attention to pupils with special needs, the author considers it is essential to join the procedures of the tutorial assessment and the psychopedagogical measurement. According to this study, the formal assessment of pupils with learning disabilities, based on the Weschler Scales criteria, confirms in a 71% of the cases the tutorial assessment estimation, However, 50% of pupils identified by the formal assessment as LD, are not perceived as having those difficulties by their tutors. The need to complement theses two assessment's ways in order to avoid the hyperidentification of the psychometrical model and the tendency towards mean values of the tutorial model is concluded from this study.