International Measures of Student Growth in Mathematics and Science Achievement: The TIMSS 2023 Longitudinal International Database

The TIMSS 2023 Longitudinal International Database represents a major advancement in international large-scale assessment by providing the first student-level longitudinal extension of TIMSS. By linking achievement and contextual data from TIMSS 2023 with a follow-up data collection in 2024, the database enables direct measurement of student growth in mathematics and science over one year of schooling. The study follows cohorts from Grades 4 to 5 and Grades 8 to 9 across participating education systems. Rich contextual, curriculum, and process data support investigations into how instructional practices, system-level policies, student attitudes, and test-taking behaviors relate to learning trajectories. As a freely available resource, the database offers new opportunities to study educational effectiveness and equity worldwide.