Exhibits 3.1 and 3.2 present achievement results for the TIMSS science content domains—life science, physical science, and Earth science at fourth grade, and biology, chemistry, physics, and Earth science at eighth grade. To examine relative performance in the content domains, TIMSS used IRT scaling to place achievement in each of the content domains on the TIMSS science achievement scales for fourth grade and eighth grade, respectively. The average scale score for each content domain is shown, together with the difference between science achievement overall and achievement in the content domain. Up and down arrows are used to indicate whether a country’s average content 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 content domains, and lower performing countries had lower achievement in the content domains. However, each country demonstrated one or two relative strengths and one or two relative weaknesses in comparison to its overall achievement.
