Trends in International Mathematics and Science Study
Boy at a blackboard

TIMSS, the Trends in International Mathematics and Science Study, is a flagship study of IEA. Directed by the TIMSS & PIRLS International Study Center at Boston College, TIMSS is an international assessment of student achievement in mathematics and science at fourth and eighth grades. Measuring trends in achievement since 1995, TIMSS data have enabled countries around the world to make evidence-based decisions to improve educational policies related to mathematics and science teaching and learning.

TIMSS assessments provide an authoritative account of how students in fourth and eighth grades perform in mathematics and science. Countries that participate in multiple cycles of TIMSS can monitor trends in student achievement while assessing changes that have occurred in curriculum, instruction, and other aspects of education that affect learning.

TIMSS focuses on effectively measuring educational achievement in mathematics and science at the fourth and eighth grades, and sometimes the final year of secondary school. The study is designed to capture the breadth and richness of these subjects as they are taught in the participating countries. The study collects detailed information about curriculum and curriculum implementation, together with empirical information about the contexts for schooling. 

Overview of TIMSS

Conducted every four years at the fourth and eighth grades, TIMSS has a quasi-longitudinal design, with the fourth grade student cohort assessed four years later at the eighth grade. Assessing fourth grade students can provide an early warning for necessary curricular reforms, and the effectiveness of these reforms can be further monitored at the eighth grade four years later.

TIMSS assessments use national curricula as the major organizing concept. Assessments are based on comprehensive frameworks that are built in collaboration with participating countries to describe the knowledge and skills expected of students at fourth and eighth grades. National Research Coordinators play an important role in helping to develop the assessment questions and questionnaires, administering the assessment, reporting the results, and interpreting the findings within their own national context.

In addition to mathematics and science assessments, the TIMSS school, teacher, student, and home questionnaires gather extensive information about the contextual factors at school and home which are associated with learning and students' achievement. These include details on how the education system is organized to facilitate learning, students' home environment and supports for learning, school climate and resources, and how instruction usually occurs in classrooms. TIMSS also publishes an encyclopedia that provides rich data about each country's educational context for learning mathematics and science.

TIMSS Participants

The map below provides an overview of all educational systems (countries and benchmarking entities) that have participated in one or more cycles of TIMSS. Please see the individual cycle pages for further details.

TIMSS Assessment Options


From the 2019 cycle onwards, an innovative computerized version of TIMSS enables countries to investigate complex areas of the mathematics and science framework that are difficult to measure with traditional paper and pencil tests. eTIMSS is an engaging, interactive assessment that encompasses the content of the paper-and-pencil version of TIMSS while also integrating problem solving and inquiry tasks designed to stimulate student motivation through items that simulate real world contexts and laboratory situations.

In 2019, countries could opt to administer the paper-based version of TIMSS. The next cycle of TIMSS will be administered in 2023.

TIMSS is appropriate for a wide range of countries. The TIMSS design accommodates countries along the performance distribution, from high to medium to low. It includes a component specially designed to measure achievement of populations that are still developing numeracy skills at the fourth grade while enabling reporting on the TIMSS mathematics scale.

TIMSS Advanced

TIMSS Advanced is an assessment for students in their final year of secondary school who are enrolled in special advanced mathematics and physics programs. It is the only international assessment that provides essential information about students' preparedness to enter university-level studies in science, technology, engineering, and mathematics (STEM). The study also collects policy-relevant data about curriculum emphasis, technology use, teacher preparation, training, and attitudes that can be used to guide education reform and policy planning in STEM fields. TIMSS Advanced was administered in 1995, 2008, and 2015.

Benchmarking Participants

TIMSS also has a benchmarking option whereby entities such as regions (e.g., states or provinces), additional grades (e.g., third or fifth grade), or additional language groups may be included in a country’s participation. Please contact IEA for further details.

Target Population

TIMSS has two target populations: the fourth grade, or the grade that represents four years of schooling, counting from the first year of ISCED Level 1; and the eighth grade, or the grade that represents eight years of schooling, counting from the first year of ISCED Level 1.

Countries also have the option of administering the TIMSS fourth-grade assessment to students in the fifth or sixth grades, or the TIMSS eighth-grade assessment at the ninth grade.

The target population for TIMSS Advanced is students undertaking advanced mathematics and physics courses in their final year of secondary school or at the start of their STEM coursework in universities.


Together with the IEA's PIRLS and ICCS, TIMSS data are recognized by UNESCO as a solid evidence base for researchers, educators, and policymakers interested in monitoring progress towards Sustainable Development Goal (SDG) 4: obtaining a quality education for all. For example, the Low International Benchmarks established by TIMSS and PIRLS are recognized as the most appropriate measures of the 'SDG minimum proficiency level' (indicator 4.1.1) for numeracy and literacy. Students who achieve this level in TIMSS fourth grade mathematics can add and subtract whole numbers, have some understanding of multiplication by one-digit numbers, can solve simple word problems, and have some knowledge of simple fractions, geometric shapes, and measurements.

Read about IEA's support for, and contribution to, SDG measures.


TIMSS, a project of IEA, is directed by the TIMSS & PIRLS International Study Center at Boston College, United States.

Other partners involved with TIMSS are Statistics Canada and Educational Testing Service (ETS) in the United States. As in all IEA studies, the international coordination and development are undertaken in close cooperation with the national research coordinators of participating countries.