International surveys of student achievement are becoming increasingly popular with governments
around the world, as they try to measure the performance of their country’s education system. The
main reason for this trend is the shared opinion that countries will need to be able to compete in the
‘knowledge economy’ to assure the economic wellbeing of their citizens. Whilst benchmark indicators
of knowledge economy ‘supply’ variables, such as investment in education as a proportion of GDP,
have been available for a long time, countries had no way of comparing the effect of their
investments and schooling in general upon students’ knowledge and skills.
Since 2000, OECD addressed this by producing a three-year cycle of ‘curriculum-independent’ tests
of reading, mathematics and science. Each cycle has major and minor emphases, with one of the
three skill areas consuming the majority of the assessment every nine years. Questionnaire
enquiries are also conducted among students and teachers to measure contextual factors. PISA tests
are taken at age 15 by representative samples of pupils in participating countries/economies, of
which there were 75 in 2009. Age 15 was selected because it was the end of compulsory schooling in
many OECD member countries when the programme was in the planning stage, but that is no longer
the case in most of those countries today.