The PAIS assessments do not follow any single national curriculum. This allows students from all countries to be compared fairly. Each subject has been influenced by curriculum content found in the national curricula of UK, Australia, Singapore, USA and others. But the PAIS assessments are skill-based, not content-based and as such do not rely on specific content from the curricula. The tests require students to think about topics rather than just recall information, and to apply their subject knowledge rather than just remember facts. The PAIS program has a similar curriculum coverage with that of large-scale international assessments such as TIMSS and PIRLS.