Teaching and learning international survey (TALIS) asks a representative sample of teachers and schools in each country about their working conditions and the learning environments. TALIS aims to provide valid, timely and comparable information on education resources to help countries review and define policies for developing a high-quality teaching profession. It is an opportunity for teachers and school leaders to provide input into educational policy analysis and development in key areas.

Lower secondary teachers and leaders of schools in 200 schools per country/economy were randomly selected (20 teachers and 1 school leader per school). Some 107 000 lower secondary teachers responded to the survey, representing more than 4 million teachers in over 30 participating countries and economies.

TALIS averages are based on all countries participating in the TALIS survey, including partner countries and economies. This explains the difference between the OECD average and the TALIS average.

The Programme for International Student Assessment (PISA) is an internationally standardised assessment that was jointly developed by participating countries and administered to 15-year-olds in schools. Tests are typically administered to between 4 500 and 10 000 students in each country.

PISA assesses how far students near the end of compulsory education have acquired some of the knowledge and skills that are essential for full participation in society. In all cycles, the domains of reading, mathematical and scientific literacy are covered not merely in terms of mastery of the school curriculum, but in terms of important knowledge and skills needed in adult life.