Education in mathematics, science, and reading shapes nations’ abilities to address the pressing challenges of our time, from climate change to the pace of technological development.

Since 1995, researchers at ɬ﷬’s Lynch School of Education and Human Development have assessed achievement worldwide, building an unparalleled trove of data that informs education research and policy in more than 70 countries. 

Parents and policymakers want to know what factors are associated with student achievement.
—Matthias von Davier, Monan Professor of Education, Lynch School; Executive Director, TIMSS & PIRLS International Study Center

The Lynch School is home to the longest-running global assessment of student achievement in science and math, IEA’s Trends in International Mathematics and Science Study (TIMSS), and the Progress in International Reading Literacy Study (PIRLS), the global standard for assessing reading achievement. Conducted every four and five years, respectively, TIMSS and PIRLS gather data on both student achievement and contextual factors ranging from socioeconomic status to student attitudes, yielding results that illuminate both the what and the why of educational achievement.

Monan Professor Matthias von Davier

Monan Professor Matthias von Davier

“Parents and policymakers want to know what factors are associated with student achievement,” says Matthias von Davier, the Lynch School’s Monan Professor of Education and executive director of ɬ﷬’s TIMSS & PIRLS International Study Center. “What role does the school system play? How does teacher training factor in? How about curriculum differences? What role are socioeconomic factors playing?”

To gather this nuanced data, the surveys combine subject-area tests with questionnaires for students, teachers, administrators, and parents. Sometimes, their findings reveal global trends. “For instance, it’s highly consistent that girls do better than boys in reading comprehension across participating countries, and that families’ self-reported socioeconomic status correlates strongly with student outcomes,” von Davier says. Although such challenges are complex, he says, TIMSS and PIRLS can provide “a trigger point for action and policy change.”


TIMSS 2023 is one of the most—if not the most—complex international studies of student achievement to date, involving hundreds of researchers, thousands of classrooms and educators, and administrators from 72 participating countries.


This year, the TIMSS & PIRLS International Study Center and colleagues at the International Association for the Evaluation of Educational Achievement (known as IEA) are conducting the eighth quadrennial TIMSS survey—the first to be delivered in a fully digital format. Conducted at two grade levels simultaneously, TIMSS 2023 is one of the most—if not the most—complex international studies of student achievement to date, involving hundreds of researchers, thousands of classrooms and educators, and administrators from 72 participating countries. Beyond national research centers and educators within countries, several international partners are contributing to translation verification, statistical sampling, test delivery software, and response scoring, among other aspects of the survey.

Transitioning to a digital format presented new challenges in developing regions, and TIMSS has accommodated a variety of options beyond fully online testing to allow delivery on USB sticks or via local infrastructure in areas where stable high-speed internet is unavailable. “The digital format allows us to assess essential skills we weren’t able to assess on paper, such as students’ ability to do online research, conduct virtual science experiments, or solve computer-based math problems,” von Davier says. 

TIMSS and PIRLS also offer fine-grained data about differences in achievement among regions and types of schools. Rather than pointing toward one-size-fits-all solutions, von Davier says, they highlight the highly specific challenges and strengths of each region and school.

Collage of prompts from TIMSS 2023 assessment

Collage of prompts from TIMSS 2023 assessment

“In one region or school, the key challenge might be improving curricula, but in another, it could be that students don’t feel comfortable because of school culture or a lack of resources. Ideally, countries use our results to better understand and address gaps and disparities.” 

When the TIMSS 2023 results are published in December 2024, the team will gear up to complete the study’s first longitudinal survey, TIMSS-L, which will reassess students in some TIMSS 2023 countries a year later to examine how achievement in participating countries grows over one year. 

“It’s rewarding to be able to support the community of education researchers with a free, accessible database,” von Davier says. “Our goal is for these results to help spark many future research projects around the world.”