This article analyzes the differences between the students of two public schools in Bogota. The selected population belongs to the lower soicial stratification in the city. Thus study has been done in the frame of massive evaluation developed in bogota from 1998 to 2001. The results of the research show the importance of the pedagogical focus on projects and the constructionof an academic community to increase the competences os the two groups. In the other hand, the text relives the quality of writing production obtained when the students writes to an audience not only the teacher evaluation. From this experience is inferred the importance of the means of comunication at school.