We recently released an analysis of PISA scores, which showed disparities in achievement across student groups and mostly stagnant scores. However, the U.S. had a better showing on another international benchmark, the TIMSS (Trends in International Mathematics and Science Study). TIMSS is different from PISA in that it assesses more classroom-based content, whereas PISA is more of an assessment of how students can apply skills learned in the classroom to real-world problems. TIMSS assesses 4^{th} and 8^{th} graders, while PISA assesses 15 year olds, regardless of grade.

In 2015, TIMSS assessed 49 countries in 4^{th} grade math, 47 countries in 4^{th} grade science, and 39 countries in 8^{th} grade math and science.

Students were assessed in math and science, but today we’ll just take a look at the math scores.

__4 ^{th} Grade Math__

U.S. 4^{th} graders scored 14^{th} out of 49 countries, with performance that was statistically lower than only 10 countries and similar to eight countries, including Finland. They also scored 10^{th} highest in the number of students who scored at the advanced level (levels are low, intermediate, high, and advanced). The percentage of students reaching high or advanced levels have increased steadily since the test was first administered in 1995. Students showed greater strength in numerical functions, but had deficits in geometric shapes and measures. They also scored higher in knowledge-based questions than items based on the application of knowledge to a problem and reasoning.

__8 ^{th} Grade Math__

U.S. 8^{th} graders were 10^{th} out of 39 countries, with seven countries having statistically higher scores and nine countries having similar scores. Eighth graders also had the 10^{th} highest number of students who scored at the advanced level, which has been steadily increasing since 1995. Students were significantly stronger in Algebra than they were in 2007 or 2011. Similar to 4^{th} graders, 8^{th} grade students were stronger at knowledge-based questions than application or reasoning questions, despite showing improvement in all three categories since 2007.

__Demographic Factors__

Schools with fewer students from affluent families and more students from disadvantaged families performed at lower levels than more affluent schools, showing that the U.S. still has much work to do to achieve academic equity. Note that demographic data is reported by principals.

Schools with more native English speakers perform better than schools with greater numbers of students learning English in both 4^{th} and 8^{th} grades. Schools with teacher-reported lack of resources and problems with school conditions also fared worse. Students who felt that they fit in, or belonged, at school had higher achievement.

__Other Contributing Factors__

The U.S. is in the bottom half of countries on measures of teacher satisfaction. Higher levels of teacher satisfaction in their schools is mildly correlated with higher student performance. Teachers who reported having greater challenges, such as large classes or administrative tasks, actually had higher student achievement than those who reported few challenges.

__International Data__

Gender gaps still tend to favor boys across the globe, though in some countries girls outperform boys. Interestingly, 8^{th} grade girls in 21 countries outperformed boys in Algebra, though boys outperformed girls in number-based problems in 17 countries.

Source: http://timss2015.org/timss-2015/mathematics/achievement-in-content-and-cognitive-domains/

As debate continues about early childhood education in the U.S., the data from other countries is quite convincing that students who have formal education before entering the K-12 system outperform those who do not. This data does not include the U.S.

Source: http://timss2015.org/timss-2015/mathematics/home-environment-support/

We still have work to do, but TIMSS shows us that improvement has been slow and steady for U.S. students.