Data analysis, probability, and measurement - as opposed to formal operations - comprised the majority (58%) of PISA mathematics items (National Center for Education Statistics, n.d.). Some schooling systems perform at a high level on both assessments, but many fare better on one or another assessment. Many Nordic and English-speaking education systems, with curricula and pedagogy oriented towards the application of knowledge in real-world settings, perform at higher levels on PISA than TIMSS, while education systems strongly oriented towards theoretically-led curriculum and instruction, such as those of Russia and former Soviet states, demonstrate higher levels of performance in TIMSS (Wu, 2010).