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.