The Australian Council for Educational Research (ACER) leads an international consortium of research organisations, and educational institutions to deliver the International PISA project on behalf of the Organisation for Economic Cooperation and Development (OECD). Translated into 48 languages and then verified to ensure they can be understood by students from a wide range of language and cultural backgrounds, PISA questions are based on relevant, everyday situations. PISA tests the reading, mathematics and science literacy of 15-year-olds across the world. In 2009 around 400 000 students from 57 countries took part.