Are Chinese, Korean and Japanese 15 year-old students smarter than their American and French equivalent? In PISA’s latest report, published in 2013, Shanghai and Singapore rank the highest in maths, science and reading, whereas France and the US are ranked far below.
Policy makers pay attention to the results from PISA. Those findings “allow them to gauge the knowledge and skills of students in their own countries in comparison with those in other countries,” according to PISA’s website.
But is this comparison really useful? Can we compare students that are working under different circumstances?
It appears that the student population in Shanghai and Singapore is far more homogeneous than the student population in France and the US. Shanghai and Singapore, which received international acclaim for their outstanding test scores, separate the local children from the children of immigrants.
Similarly, in Switzerland, which is well ranked compared to other Europeans nations, students with mediocre grades at school are directed toward apprenticeships.
In comparing school system, you need to take into account all those confounding factors. If the schooling population in Singapore and Shanghai changed in such a way that it became similar to the schooling population in France and the US, than we do not know how the ranking would change.
Therefore, this ranking does not tell us which schooling system is better.