exhibit-1-1

The 2023 cycle marked the full transition to a computer-based assessment system, incorporating an adaptive booklet rotation to balance the proportion of more and less difficult booklets for countries with very high or very low expected average achievement. The 2023 assessment was carefully designed using a balanced incomplete block design, adhering to industry standards, and analyzed with state of the art psychometric models. Consequently, the TIMSS 2023 mathematics achievement results for all 58 countries and 5 benchmarking participants are reported on the same TIMSS fourth-grade mathematics scale. The TIMSS fourth-grade mathematics achievement scale was established in TIMSS 1995, based on the combined distribution of achievement data across all participating countries, treating each country equally. A centerpoint of 500 was set to correspond to the mean of overall achievement in 1995, with 100 points set to correspond to the standard deviation. Students’ achievement is placed on the scale with each subsequent TIMSS cycle, most recently for TIMSS 2023.

Exhibit 1.1.1 reports the average mathematics achievement estimates at the fourth grade based on the 58 TIMSS 2023 participating countries and the 5 benchmarking entities. The exhibit also presents the corresponding confidence intervals, and standard deviations for each participating country, together with the associated standard errors for these estimates (given in parentheses). Additionally, it includes a visualization of the score distribution, illustrating percentiles of the distribution and the confidence interval of the average achievement, and includes an international average for the participating countries.

Sorted by average achievement, the exhibit shows that the countries with the highest estimated average achievement are Singapore, Chinese Taipei, Korea, Hong Kong SAR, and Japan. That is, among the highest ranking countries are the participating countries from East Asia – as in previous TIMSS cycles. In these countries, the average achievement can be as high as 615, for example in Singapore, with a 95% confidence interval ranging from 609 to 620. The confidence interval provides a score range around the estimated mean. Intervals constructed in this way around the estimated average have a 95% chance to include the true average of the country’s achievement.

Notably, there is considerable variability in achievement within each country, as indicated by the standard deviation of achievement shown in the table. Therefore, it would be incorrect to assume that (all) students in Singapore (or any other country) achieve higher scores than students in another country. While the average achievement of one country may be higher than the average achievement in another country, each country has some lower-achieving students and some higher-achieving students.

While examining the average achievement across countries can provide an overall initial impression of achievement in participating countries, the data provided by TIMSS 2023 is more comprehensive. As presented here, TIMSS also provides results that inform about the range of achievement observed in each country, and in later sections about associations with contextual factors, providing a deeper understanding of student performance.