How much do we know about what our students know of statistics?

Owing to the shortage of didactic preparation which teachers possess after their academic formation, the novices are obliged to learn at a very quick pace the functioning of the dynamic school. With so much novelty, evaluation stands out in the broad sense and also as the receiver of all information. In this paper we examine the method of work by means of an example, in projects of statistical education and their evaluation through a trainee portfolio analysing the information obtained and using it as a source to regulate the inter-action in the classroom. This will help us to appreciate the grade of knowledge acquired by the students in certain concepts of statistics proposed in the Spanish curriculum for students from 15-16 years in obligatory secondary education.