Assessment Opinion

STEM Education: Lessons From 20 Years of Data

By Ina V.s. Mullis & Michael O. Martin — June 25, 2019 8 min read

Drs. Ina V.S. Mullis and Michael O. Martin are executive directors of the TIMSS & PIRLS International Study Center at Boston College.

As the number of jobs in STEM fields and the related demand for STEM skills grows, discussion among educators and policymakers is increasingly focused on how well students are being prepared to meet these needs. Simultaneously, interest is growing in how other countries prepare their students in crucial STEM-related subjects at school.

Beginning in 1995 and every four years since, TIMSS—the Trends in International Mathematics and Science Study sponsored by the International Association for the Evaluation of Educational Achievement (IEA)—has measured student achievement around the world, providing comparative information about how well students are learning mathematics and science and the home and school factors associated with achievement. Having monitored student learning in mathematics and science for 20 years and counting, TIMSS is a unique source of data on how well—and how—countries are preparing their students for the future, providing lessons that can inform policy and practice. In 2015, the most recent year for which data are available (TIMSS 2019 results will be released next year), 60 countries and benchmarking entities participated in TIMSS.

What are some things we have learned from TIMSS about mathematics and science education around the world? Previously news coverage of the TIMSS 2015 international results focused almost exclusively on top performers and countries’ achievement trends, but this article will analyze the considerable additional data of TIMSS 2015.

East Asian Students Continue to Outperform Their Peers

In 2015, Singapore, Hong Kong, South Korea, Chinese Taipei, and Japan were the highest-achieving countries in 4th and 8th grade mathematics, maintaining a long-running edge. There was a 23-point gap at grade 4 and a 48-point gap at grade 8 between these countries and the next highest-scoring countries. The United States trailed further back, with an average score below 10 countries at grade 4 and seven countries at grade 8.

These East Asian countries dominated in science as well, joined at the top by the Russia Federation at grade 4 and Slovenia at grade 8. The United States lagged behind eight countries at both grades in science.

Across the world, achievement trends over time are encouraging for countries that participated in 1995 and 2015, with many improving over the two decades and few declining. In the United States, mathematics achievement increased at both grades over that period, while average achievement in science increased at grade 8 but was flat in grade 4.

The TIMSS International Benchmarks—Low, Intermediate, High, and Advanced—are achievement levels, signifying increasing levels of knowledge and skills. Using this measure, the East Asian countries also had the best performance in mathematics in 2015: At least 93 percent of 4th grade students reached the Intermediate Benchmark, substantially more than the international average of 75 percent. And 32 percent to 50 percent of students in these countries reached the Advanced Benchmark, compared with 6 percent internationally. In grade 8, in Singapore, Chinese Taipei, and South Korea, 43 percent to 54 percent of students reached the Advanced Benchmark in mathematics, but in many TIMSS countries, only 10 percent or fewer students did.

In 4th grade science, Singapore, South Korea, Russia, and Japan had the strongest performance at the TIMSS International Benchmarks, with 90 percent or more of their students reaching the Intermediate Benchmark versus 77 percent internationally. These top countries also had 19 percent to 37 percent of their students reach the Advanced Benchmark, versus an average of 7 percent of students internationally. At grade 8, 42 percent of students in Singapore and about a quarter of students in Chinese Taipei (27 percent) and Japan (24 percent) reached the Advanced Benchmark, but less than 10 percent did in many TIMSS countries.

20-Year Shifts in the Gender Gap in Science

Twenty years ago, TIMSS 1995 found that gender differences in mathematics were generally small or negligible at both 4th and 8th grades, though in countries where there was a significant gender difference, it was always boys that held the advantage. In science, the boys’ advantage was more pronounced, with boys outperforming girls in about half the countries at 4th grade and nearly all countries at 8th grade. But 2015 showed us quite a different picture with regard to gender differences. In 2015, about half of TIMSS countries had gender equity in achievement, ranging from 47 percent of the countries in 4th grade mathematics to 67 percent in 8th grade mathematics. Overall, there were far fewer countries with gender differences favoring boys and quite a few countries in which girls outperformed boys, particularly in science.

Looking only at the countries that participated in TIMSS 1995 and 2015 (17 at 4th grade and 16 at 8th grade), we also see this shift in gender differences in science achievement away from boys having the advantage to more countries where there is no significant difference between average achievement of boys and girls. For example, in 13 countries, there was no significant difference between 8th grade boys’ and girls’ average achievement in 2015, while in 1995 this was the case in only one country. In mathematics, the shift among this restricted set of countries was less pronounced.

Curricula Worldwide Allocate Significant Instructional Time to Mathematics and Science

The amount of time spent on mathematics and science lessons is a crucial resource, though more time does not automatically equate to higher achievement. The TIMSS 2015 countries reported their official curricula allocated one-fourth to one-third of total instructional time in primary and lower-secondary schools to mathematics and science education combined. And school principals’ and teachers’ reports indicate that the average number of hours devoted to mathematics and science from 1995 to 2007 to 2015 has remained relatively stable.

TIMSS 2015 results show that internationally, more time continues to be spent on mathematics at grade 4 than grade 8, from an average of 157 annual hours at grade 4 to 138 hours at grade 8. U.S. students, by comparison, spent 216 hours at grade 4 and 155 hours at grade 8.

In science, there was more time allotted to lessons at grade 8 among the TIMSS 2015 countries: 76 hours at grade 4 and 144 hours at grade 8, on average. In the United States, students on average were in science lessons for 100 hours annually at grade 4 and 144 hours at grade 8.

Presence of Computers in the Classroom Varies Worldwide

Most TIMSS 2015 countries reported having specific policies around the use of Information and Communications Technology (ICT) in their mathematics and science curricula. These could include general suggestions about integrating ICT into instruction to specific suggestions involving problem solving, dynamic geometry, and representing data through tables and graphs in mathematics and simulating investigations and visualizing abstract concepts in science.

However, the pervasive inclusion of ICT in curriculum guidelines doesn’t always translate to widespread use of technology in instruction. Even as digital devices have a growing presence in our lives, the extent to which they are used in the classroom varies worldwide. Teachers in TIMSS 2015 reported a wide range of computer availability for mathematics and science lessons. Internationally, an average of 37 percent of 4th grade students had access to computers for mathematics lessons, but that ranged from 89 percent of 4th graders in New Zealand to 3 percent in Croatia. The United States was closer to the global average, at 46 percent.

Teachers’ Paths to Joining the Profession Have Grown More Rigorous

Around the world and over time, the requirements for becoming a teacher have grown more rigorous. In TIMSS 2015, most countries reported that their 4th and 8th grade teachers receive at least a four-year university degree. Some countries stipulate a five-year program or master’s degree and some also reported tougher admissions criteria to teacher education programs by requiring minimum grade point averages, testing of candidates, or requiring interviews. In 1995, however, in about half the countries, only a three-year program at a teacher-training institution was required to teach 4th grade.

Students Enjoy Learning Mathematics

Contrary to what many people believe, students like learning mathematics—over the 20 years of TIMSS, they have consistently indicated enjoying it. And, as one would expect, students who enjoy learning mathematics are better at it than students who do not. At the 4th grade level in 2015, 81 percent of students internationally said they liked learning mathematics; enthusiasm was lower at 8th grade, at 61 percent. Enjoyment of learning science stayed strong, from 89 percent at 4th grade to 81 percent at 8th grade.

Ongoing Lessons in Mathematics and Science Education

Over its 20 years, TIMSS has enabled countries to: measure how well their students perform in mathematics and science over time; study which factors at home and school are associated with achievement; and observe how other countries are preparing students in STEM subjects. TIMSS data will continue to inform policymakers and educators on student achievement. This spring, students in nearly 70 countries and benchmarking entities participated in the TIMSS 2019 assessment, with results to be released in December 2020. This time, the assessment was enhanced with the introduction of eTIMSS, a digital version of the assessment that also includes interactive problem solving and investigation tasks based on real-world and laboratory situations.

With the upcoming 2019 results, countries that have participated in TIMSS since its inception in 1995 will have the longest trend line of any international mathematics and science study. As educators and policymakers continue to best prepare their students in STEM subjects, they have a wealth of information to turn to.

To learn more, explore the TIMSS 2015 International Results in Mathematics, TIMSS 2015 International Results in Science, 20 Years of TIMSS, and the TIMSS 2015 Encyclopedia: Education Policy and Curriculum in Mathematics and Science.

Connect with TIMSS & PIRLS International Study Center and the Center for Global Education on Twitter.

Images created by, and used with permission of, IEA’s Trends in International Mathematics and Science Study—TIMSS 2015.

The opinions expressed in Global Learning are strictly those of the author(s) and do not reflect the opinions or endorsement of Editorial Projects in Education, or any of its publications.

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