PISA is the OECD's Programme for International Student Assessment. Every three years it tests 15-year-old students from all over the world in reading, mathematics and science. The tests are designed to gauge how well the students master key subjects in order to be prepared for real-life situations in the adult world. Why choose 15-year-olds? Because in most countries, at the age of 15, students can decide whether or not they want to continue their education. They therefore need to be equipped for adult life. PISA publishes the results of the test a year after the students are tested to help governments shape their education policy. PISA cycles are referred to by the year in which the students were tested. Therefore PISA 2000 means the students were tested in the year 2000, PISA 2003, in the year 2003 and so forth.