The IEA studies focus on the output of educational systems - that is, the attitudes and educational achievements of students - and attempt to relate these outputs to those inputs that have an effect on them. The overriding goal is to learn more about the factors that influence student attitudes and achievement which may be manipulated to bring about improvements in attitudes and achievement, or efficiencies in the educational enterprise.

IEA studies have a strong empirical basis, and they rely mainly on cross-sectional and longitudinal non-experimental designs, with data collection through sample survey methods. Studies make use of qualitative methods such as case studies and observational techniques when appropriate, but the main thrust of IEA studies has been to bring a strong quantitative orientation to the description and analysis of large-scale survey data.

At the heart of most IEA studies is a cross-national sample survey of student achievement in one or more school subjects. Student achievement is measured by administering objective tests to a sample of the students who have been selected as representative of national populations. Information about the students’ backgrounds, attitudes and interests is collected by means of self-report questionnaires. Questionnaires are also adopted for collecting information from teachers about their experiences, attitudes, and classroom practices, and from school principals about the characteristics of schools that the students attend.

IEA operates at the primary and secondary level of schooling.