These exhibits present achievement results for the three TIMSS cognitive domains—knowing, applying, and reasoning. To examine relative performance in the cognitive domains, TIMSS used IRT scaling to place achievement in each of the cognitive domains on the TIMSS science achievement scales, for fourth and eighth grades, respectively. The average scale score for each cognitive domain is shown, together with the difference between science achievement overall and achievement in the cognitive domain. Up and down arrows are used to indicate whether a country’s average cognitive domain score is significantly higher or lower than its overall science average score.
Generally, the highest performing countries overall had the highest achievement in the cognitive domains and lower performing countries had lower achievement in the cognitive domains. However, most of the countries demonstrated at least one relative strength compared to overall science achievement; and at least one weakness.
