The paper tries to show how the impact of PISA unexpectedly extends to fields such as that of student mobility producing, inside an evolving school system such as the Italian, some interesting effects. The analysis is the result of field research trying to understand the attitude of Italian secondary school teachers about individual long term student exchanges. This attitude has been studied by observing how teachers act towards returnees, the assessment of competencies the latter have acquired abroad, being a central moment of this acting. Such assessment is problematic because the Italian system does not give clear rules on how to assess the knowledge and the competencies acquired abroad. Two case studies show how, in the void left by inadequate legislation on this topic, some teachers have drawn inspiration from the evaluation of competencies in the PISA tests.
