IEA became a legal entity in 1967. Its origins, however, date back to 1958 when a group of scholars, educational psychologists, sociologists, and psychometricians met at the UNESCO Institute for Education (UIE) in Hamburg, Germany, to discuss problems associated with evaluating school effectiveness and student learning. They argued that effective evaluation requires examination of both the inputs to education and its outcomes (such as knowledge, attitudes, and participation).

The founders of IEA viewed the world as a natural educational laboratory, where different school systems experiment in different ways to obtain optimal results from educating their youth. They assumed that if research could obtain evidence from across a wide range of systems, the variability would be sufficient to reveal important relationships that would otherwise escape detection within a single education system. They strongly rejected data-free assertions about the relative merits of various education systems, and aimed to identify factors that would have meaningful and consistent influences on educational outcomes.

The first IEA study, conducted in 1960 in 12 countries, assessed 13-year-old students' achievement in mathematics, reading comprehension, geography, science, and non-verbal ability. The aim of this research, known as the Pilot Twelve-Country Study, was to investigate the feasibility of more extensive assessments of educational achievement. The study produced findings of academic and practical value, but more importantly demonstrated the feasibility of conducting large-scale, cross-national surveys.

Today, many educational stakeholders around the world are convinced of the value of conducting comparative, large-scale assessments in education, and IEA continues to play a key role in this important field of research.

Access our 60 years of IEA (1958-2018) publication for more IEA stories.

Early IEA Studies

The encouraging findings of the Pilot Twelve-Country Study gave rise to the First International Mathematics Study (FIMS), which employed an improved sampling procedure and an extended test of student achievement. Data were collected in 1964 in 12 countries from two populations (13-year-old students and final-year secondary students). The study found that ‘opportunity to learn’, which refers to how a subject is actually taught in the classroom, in contrast to how it is prescribed in the curriculum, was a remarkably good predictor of systematic differences in student performance. The study also showed that all school systems suffer, to some extent, from lack of equity across different groups of students.

The Six Subject Survey (1970–1971) expanded the scope of investigation to science (known as the First International Science Study, or FISS), reading comprehensionliterature educationEnglish as a foreign languageFrench as a foreign language, and civic education. The researchers moved the target population from 13 to 14 years of age because by that time nearly all participating countries were keeping children in fulltime compulsory education until they reached their 15th birthday. The researchers also included additional populations (10-year-old students and final-year secondary students) for some subjects. The survey helped to identify new predictors of student achievement related to interests, motivation and attitudes, methods of teaching, and school practices.

In 1971, IEA organized a seminar on curriculum development and evaluation in Gränna, Sweden. Researchers and curriculum experts from 23 countries participated. It is often said that this seminar had a major influence on curriculum development in the majority of countries that attended.

Periodic Studies

During the late 1970s, several researchers suggested that periodic studies of the key subject areas might allow IEA to measure changes in educational achievement over time. This thinking led to the Second International Mathematics Study (SIMS), which was conducted in 20 countries in 1980–1982, and the Second International Science Study (SISS), which was carried out in 24 countries in 1983–1984. The strategy of repeating a study over an interval of several years provided participating countries with important information on trends in their students’ standards of achievement in mathematics and science.

While SISS was a deliberate replication of FISS, SIMS incorporated a short-term longitudinal component. The Classroom Environment Study (1981–1983) was also longitudinal, and studied the effects of teaching behavior on student learning outcomes in nine countries; during this study, and with SIMS, the participating countries tested the same students on two separate occasions. However, it became evident that conducting measurements over only two points of time was not enough to yield the information needed to accurately estimate the effects of schools and teaching behaviors on educational achievement.

By the beginning of the 1980s, more children around the world were being enrolled in preprimary education. IEA’s member countries considered that more should be known about the cognitive, attitudinal, social, and emotional development of children in different preschool settings, including the home environment. The longitudinal Preprimary Project (PPP) addressed this interest by examining how children’s early experiences at age four affected their later cognitive and language development at age seven. Seventeen countries participated in one or more of the three phases of the study, conducted in 1987–1989, 1992, and 1995–1997, respectively.

Further studies included the Written Composition Study, which was conducted in 1984–1985 in 14 countries. It examined the teaching and learning of written composition by assessing students near the end of primary schooling, students near the end of compulsory schooling, and students near the end of academic secondary school in order to identify the associated beliefs and conventions. The study assessed six types of writing according to the dimensions of style and tone, overall impression, content, and organization, with particular attention paid to cultural background, curriculum, and teaching practices.

Levels of reading literacy of 9-year-old and 14-year-old students across countries, as well as the nature of reading instruction and relationships between reading comprehension and aspects of home and school environment were examined in the Reading Literacy Study, which was conducted in 1990–1991.

Policy Demands

The 1990s brought new challenges and successes. As a result of government programs, computers began to play a more significant role in school education. The Computers in Education Study (COMPED), conducted in 1989 and 1992, aimed to describe and analyze various aspects of the introduction and use of computers in participating countries. Stage 1 of the study was a descriptive survey that investigated computer use at the elementary, lower-secondary, and upper-secondary levels. The first part of Stage 2 was a follow-up to Stage 1, enabling a longitudinal study of trends. The second part involved assessing the effects of schools, teachers, and classroom practices on student outcomes in the domain of computer usage in schools.

The Second Information Technology in Education Study Module 1 (SITES-M1) provided an update on the state of affairs in 26 countries, investigating computer technology resources and their use and integration into the instructional process; data were collected in 1998–1999. SITES-M2 (2001) was a qualitative study, based on case studies of innovative pedagogical practices using information and computer technology (ICT) in 28 countries. Five years later, SITES 2006 explored what countries’ efforts to promote the pedagogical use of ICT had achieved since the SITES-M1 data collection.

Political changes resulting from the collapse of communism in the Soviet Union and central-eastern Europe raised new questions about education of the “good citizen.” To answer these questions, the Civic Education Study (CIVED) investigated 14-year-old students’ civic knowledge and engagement, as well as related policies and practices. Thirty-one countries, including nine former communist countries, participated in one or both phases of the study (1996–1997 and 1999).

Another study that aimed to meet the policy demands of the late 1990s was the Language Education Study. Initially planned as a three-phase project but due to lack of funding only Phase 1 regarding the policy context was completed. Twenty-five countries participated in this phase of the project in 1995. These countries collected data on second and foreign language education and polices for four languages: English, French, German, and Spanish.

Cycles of Studies

The Third International Mathematics and Science Study (TIMSS 1995) was the first in a four-year cycle of assessments in mathematics and science, now known as the Trends in International Mathematics and Science Study. With 46 participating countries and over half a million students in five grades, it was also the largest and most ambitious study of comparative education undertaken at the time. As an additional option, some countries tested two special subgroups of final-year secondary students enrolled in advanced mathematics and/or physics courses. This option later became known as the first cycle of TIMSS Advanced. Subsequent regular data collections for TIMSS took place in 1999 (also known as TIMSS-Repeat), 20032007, Advanced 20082011, 2015, Advanced 2015, and 2019. All of these assessments were conducted at the fourth and eighth grades. TIMSS 2023 marks the eighth cycle of the study.

The Reading Literacy Study (1990–1991), with 32 participating countries, was a milestone for IEA. It was characteristic of other IEA studies in its focus on both student achievement and educational contexts. The study also collected background information on students’ voluntary reading activities. The Reading Literacy Study was a major step forward for IEA, acting as a predecessor of PIRLS.

The Progress in International Reading Literacy Study (PIRLS) has been conducted in five-year intervals, to date 2001200620112016, and 2021. PIRLS investigates changes over time in children’s reading achievement at the fourth grade, an important transition point in their development as readers. The study also gathers information on reading education and children’s early experiences at home and school in learning to read. In 2011, PIRLS Literacy (formerly known as prePIRLS) was offered for the first time for countries whose fourth grade students were still developing fundamental reading skills. In 2016, ePIRLS was launched, an innovative assessment of online reading enabling participating education systems to understand how successful they are in preparing fourth grade students to read, comprehend, and interpret online information. This option was further developed into digitalPIRLS for PIRLS 2021. PIRLS 2026 marks the sixth cycle of the study and will complete the transition to fully digital assessment.

IEA’s cycle of trend studies in basic school subjects continues to attract an increasing number of countries from all around the world. More than 45 education systems participated in PIRLS and over 60 education systems joined TIMSS in 2011, a year that marked a unique event—joint assessment at the fourth grade—in the history of both cycles. Some participants were ‘newcomers’ to international assessment, while many others represented low- or middle-income countries whose social, political, and economic situations differ from the countries that have traditionally participated in IEA studies.

Continuous Evolution

The first decade of the new century brought two meaningful developments to IEA studies: creating a base for new cycles (civic education, advanced mathematics, and science), and entering new areas of assessment (computer and information literacy of students, teacher education). We also continued to develop and adapt our existing studies to keep pace with progress in educational assessment and policy.

The first International Civic and Citizenship Education Study (ICCS 2009) investigated the ways in which young people in 38 countries were prepared to undertake their roles as citizens. ICCS 2009 assessed changes over time since CIVED. It also broadened the scope of research by introducing novel regional modules for Asia, Europe, and Latin America. This approach allowed the countries in these regions to address questions important in their specific contexts.

The second cycle of the study, ICCS 2016, also investigated students' knowledge and understanding of concepts and issues related to civics and citizenship, as well as their beliefs, attitudes, and behaviors. For countries that participated in ICCS 2009, the study was designed to monitor trends in civic knowledge and engagement over seven years.

For ICCS 2022, IEA is working in collaboration with UNESCO to incorporate indicators of knowledge and understanding, skills, beliefs, attitudes and behaviors relating to Global Citizenship Education (GCED), and Education for Sustainable Development (ESD), with the aim of helping countries monitor progress toward the new sustainable development goals (SDGs), particularly target 4.7. ICCS is now the world's longest running international civic education study.

The Teacher Education and Development Study in Mathematics (TEDS-M) was IEA’s first study of tertiary education. It examined the policies, programs, and practices for preparing elementary and lower-secondary mathematics teachers in 17 countries.

In response to continuing interest in ICT as a “21st century skill,” IEA initiated the International Computer and Information Literacy Study (ICILS) in 2013. The aim of this study was to evaluate students’ understanding of and skills in using computers via an authentic computer-based assessment for eighth grade students. ICILS 2018 is linked directly to ICILS 2013, allowing countries that participated in the previous cycle to monitor changes over time in computer and information literacy achievement and its teaching and learning contexts. ICILS 2018 also introduced a new, option computational thinking. This domain included not only programming but also structuring and manipulation data sets. ICILS 2023 will consider how prepared students are for study, work, and life in a digital world.