The OECD Programme for International Student Assessment (PISA) is a collaborative process among the 43 participating countries, bringing together scientific expertise from the participating countries and steered jointly by their governments on the basis of shared, policy-driven interests.PISA is an unprecedented attempt to measure student performance across countries, as is evident from some of its features: - The literacy approach: PISA aims to define each domain (reading, mathematics and science) not merely in terms of mastery of the school curriculum, but in terms of the knowledge and skills needed for full participation in society.- A long-term commitment: Over the decade to come, it will enable countries regularly and predictably to monitor their progress in meeting key learning objectives.- The age-group covered: By assessing 15-year-olds, i.e. young people near the end of their compulsory education, PISA provides a good indication of the overall performance of school systems.- The relevance to lifelong learning: PISA does not limit itself to assessing students' knowledge and skills but also asks them to report on their own, self-regulated learning, their motivation to learn and their preferences for different types of learning situations.