SUMMARY
This paper critically analyze the forms of knowledge that are tested in PISA from a critical realistperspective. After a initial and fundamental differentiation between two forms of knowledge,unmasks false beliefs or assumptions about the characteristic features of these two forms ofknowledge and about the problematic relationship between knowledge and its assessment. Therelationship between knowledge and its assessment is further aggravated by various ‘examinationtechnologies’ such as whether an incentive is attached to the taking of the test, the students’motivation to take the test and the test format, which might favour some groups in comparisonwith others. International comparative student assessments (like PISA) face the additionaldifficulty of trying to construct curriculum-free tests underpinning the idea of a universal form ofknowledge. This notion makes a number of reductionist assumptions and does not account properlyfor cultural differences which might affect test performance in several ways. The final criticism isdirected at the way PISA results are published in comparative national tables thereby puttingemphasis on position rather than score.