John Jerrim.

Every time PISA results are released, concerns are raised about the methodology that underpins the work.

One area that has come in for repeated criticism is how the test scores of students are actually produced, as in this article, which asked whether PISA was “fundamentally flawed”.

Such concerns were exacerbated by a seminal paper by Svend Kreiner and Karl Bang Christensen who claimed that their results indicated that using PISA to compare countries was “meaningless”.