TIMSS and PISA both assess aspects of mathematical skills; however, they differ in terms of whom they assess and what they measure. TIMSS assesses 4th- and 8th-graders' knowledge of specific mathematical topics and cognitive skills that are closely linked to the curricula of the participating countries. PISA assesses 15-year-old students' mathematics literacy, which it defines as
An individual's capacity to identify and understand the role that mathematics plays in the world, to make well-founded judgments and to use and engage with mathematics in ways that meet the needs of that individual's life as a constructive, concerned, and reflective citizen (OECD, 2006, p. 12).
On account of these different aims, the two assessments ask students to perform different tasks. TIMSS asks 4th- and 8th-graders to complete a range of multiple-choice and short constructed response questions that test their knowledge of specific mathematics topics or content domains—numbers (manipulating whole numbers and place values; performing addition, subtraction, multiplication, and division; and using fractions and decimals), geometric shapes and measures, and data display at grade 4; and numbers, algebra, geometry, and data and chance at grade 8. 28
In contrast, PISA does not focus exclusively on outcomes that can be directly linked to curricula, but instead emphasizes real world applications of mathematical knowledge. PISA's content domains are defined in terms of the manner in which mathematical knowledge is likely to be encountered in the larger world: space and shape, change and relationships, and uncertainty. Thus, PISA presents students with a variety of situations or problems in which, as young adults, they are likely to encounter numbers and mathematical concepts. These can range from estimating an area or comparing the best buy for a product to interpreting the statistics in a news report or government document. Most questions are multiple-choice, but there are some constructed response questions as well which could ask students to explain a mathematics principle, show their calculations, or explain their reasoning. 29 PISA complements information obtained from studies such as TIMSS because it addresses whether students can apply what they have learned both in and out of school. 30
It is important to note that PISA's mathematics assessment was revised in 2003 to broaden the content domains covered. (The PISA 2000 assessment did not cover uncertainty.) Because of this change, comparing mathematics literacy scores from PISA 2000 with those of later PISA assessments is inappropriate.
28 Examples of TIMSS mathematics items can be viewed at http://timss.bc.edu/timss2007/items.html.
29 Examples of PISA mathematics items can be found in OECD 2007, pp. 306–311 (available at http://www.oecd.org/dataoecd/30/17/39703267.pdf).
30 For a more detailed comparison of TIMSS and PISA, see Neidorf et al. 2006.