The purpose of this article is to uphold observation categories for the didactic interaction within the classroom between the teacher and his/ her students, related to the cognitive development. The analysis is carried out starting from two study approaches: the socio-ethnographic linguistic and the socio-cognitive approach. The categories analyzed by means of the Kappa rate give results of good and very good observer agreement and at the same time the exchanges according to their high or low cognitive exigency combine significantly to mediation and cognitive function criteria, raised by the experience model of mediate learning. The categories that can be observed show a conversational and cognitive significance and are revealed in different ways during the development of the lesson.