This document provides an overview and comparison of the Trends in International Mathematics and Science Study (TIMSS) and the Program for International Student Assessment (PISA). TIMSS assesses the mathematics and science achievement of 4th and 8th grade students internationally every 4 years, while PISA assesses the practical mathematics, science and reading skills of 15-year-olds every 3 years. Both studies aim to inform education policies, although TIMSS focuses more on linking achievement to curriculum and instruction, while PISA focuses more on students' preparedness for adult life. The frameworks of TIMSS and PISA mathematics assessments are generally comprehensive, but PISA's framework emphasizes the application of mathematics in daily life more than problem solving