Tier Ducks

The latest international test results are in, and they bring mostly good news for US educators. Yesterday's release was the fourth edition of the Trends in International Mathematics and Science Study (TIMSS) since the original 1995 administration. Rather than use TIMSS merely for hyperbole, it's worthwhile to look at them more holistically.

First, TIMSS should not be used merely for rankings. While it's technically accurate to say the US had the ninth highest score in 8th grade math, for example, just that number alone does not do justice to the truth. Five countries (Chinese Taipei, the Republic of Korea, Singapore, Hong Kong, and Japan) scored significantly above us, five countries scored about where we did (Hungary, England, Russia, Lithuania, and the Czech Republic), and 37 countries scored well below us (including places like Australia, Sweden, and Norway). Similar tiers exist across fourth and eighth grades for math and science.

The results are meant to show interesting across-time comparisons as well, and in that respect, we're doing quite well. Our scores have risen both in raw numbers and against the average. At the same time, we've also narrowed gaps in mathematics since 1995 for blacks and whites, whites and Hispanics, and low- and high-achievers:

• 4th grade white-black gap fell from 84 to 67
• 4th grade white-Hispanic gap fell from 48 to 46
• 8th grade white-black gap fell from 97 to 76
• 8th grade white-Hispanic gap fell from 73 to 58
  

Despite this progress, the biggest difference in the scores of US students is not between countries, but rather remains within our own. In fourth grade math, the effect size of US students attending high-income versus low-income schools is 1.4 times as large as the difference between US students and the highest performing country. In science, the effect size by income is three times what it is between the US and the leading nation. Income gaps continue to persist at levels higher than all others, and that should be the real story out of these results.