Pisa tests attempt to show which nations are leading the way for education on everything from maths and science to reading.
Nations place great stock in their position in these tables, hoping to place as highly as possible.
But where do these tests come from? How do they work? When do they take place? And what are children tested on? Here are our answers to all of your Pisa questions.
The latest Pisa results for 2022:
UK’s Pisa scores fall in maths, reading and science
What are the Pisa tests?
The Programme for International Student Assessment (Pisa) tests are a way of comparing the academic performance of students in different countries around the world.
Pisa is run by the Organisation for Economic Cooperation and Development (OECD), an intergovernmental organisation.
What subjects are tested in the Pisa tests?
The 2022 tests were focused mainly on mathematics.
There are also minor assessments on reading, science and global competence and financial literacy.
Each set of tests has a different focus, rotating mathematics, reading and science.
The tests are designed to not just test knowledge but also the students’ ability to use their reading, mathematics and science knowledge and skills to tackle real-life challenges.
Who takes the Pisa tests?
Pisa tests are taken by 15-year-olds in the schools of the 79 participating countries. This far-reaching list includes Azerbaijan, Argentina, Germany, Mexico, Spain, Singapore, Zambia - and the UK.
The number of children who take the test in each country varies depending on the size of the population, but the majority of participating countries have 80 per cent of their 15-year-olds taking the test.
In order to get a representative sample of each country’s 15-year olds, Pisa has a minimum sample number required for every country and economy.
For countries taking the tests on computers, the sample needs to be made up of at least 6,300 students. For countries taking the tests on paper, the sample needs to include at least 5,250 students.
These students must come from a minimum of 150 different schools.
Cath Jadhav, national strategic account leader at exam board Pearson and formerly executive director for standards, research and analysis at Ofqual, who was involved in the administration of the tests in England, Wales and Northern Ireland in 2022, says: “In England 175 schools took part and 5,045 pupils took the tests. In Wales 90 schools took part and 2,604 pupils took the tests, and in Northern Ireland 80 schools took part and 2,401 pupils took the tests.”
What sort of questions are in the Pisa tests?
Two-thirds of the Pisa tests are multiple-choice questions, with the remaining third being open-ended questions. Where possible, the tests are taken on a computer.
The questions that are in the Pisa tests are the same all around the world, but each country has them translated into its own language.
Not all students answer the same questions, even within the same country. There are sample questions from the different countries that you can find on the OECD website.
Jadhav explains that the wording of the translations required some small adjustments to suit the country where the test was taken.
“We had subject experts who reviewed the language in the questions,” she says. “For example, for American-English speakers, the word ‘trunk’ means the storage space in a car. So for English speakers in England, Wales and Northern Ireland, this would need to be changed to ‘boot’.”
How long do the tests take?
In countries where the tests can be taken on a computer, there are two tests that each last one hour.
The tests are conducted using “adaptive testing”, whereby the questions a student is given depend on how well they answer the previous question, and the questions are designed to get progressively harder as the test goes on.
In total, there are 546 different questions, and these total 15 hours of assessment.
What other information is collected during the Pisa tests?
As well as testing students on academic subjects, Pisa also surveys young people on their attitudes to education and asks them about their motivations.
For example, in 2018 students were asked if they feared failure, if they had ever “skipped school” and if they agreed or disagreed with the statement: “Your intelligence is something about you that you can’t change very much.”
How often are the Pisa tests held?
The tests are taken every three years. The latest tests were taken in 2022, and every participating school has an eight-week window when they need to take the test.
What is the scoring system in Pisa?
The Pisa scores are calculated by subject, and each student is awarded a scaled score.
Around two-thirds of students across all countries receive a score between 400 and 600. Only 2 per cent receive a score above 700, and a handful in each country achieve a score above 800.
Countries are ranked by their performance in each individual subject, and not a combined score.
Due to the way the tests are conducted, each country is given an upper rank and a lower rank to reflect the fact that the tests only reflect a sample of students in that country.
Each question is worth either one or two marks. Jadhav says that on average students will answer “between 50 and 65 questions over two hours”.
What do the Pisa results show?
It is possible to make comparisons with previous years from the Pisa data.
However, the OECD does caution against comparing performance from one Pisa release only with the previous one, saying: “Real change in education is cumulative and often slow; with good measurement, one should expect gradual improvement or decline.”
It adds that “year-to-year comparisons may not be significant” and that instead trends should be identified when it is an “accumulation of short-term changes that point in the same direction”.
Jadhav explains that the test design allows comparisons with previous years.
“Questions that were put to cohorts in previous Pisa tests will appear again,” she explains. “This way we can confidently compare performance over time, as we can see how students from different years responded to the same questions.”
Which countries do best?
In the last Pisa data released in 2023, China topped the charts for science, maths and reading, with Singapore, Estonia, Canada, Japan and Finland all in the mix, too.
Scores fell in England, Scotland and the UK as a whole, although their international rankings have improved in maths and reading since the last survey in 2018.
