PISA is an acronym for the Programme for International Student Assessment, an international assessment that measures 15-year-old students' achievement in mathematics, reading, and science literacy. PISA is coordinated by the Organisation for Economic Co-operation and Development (OECD) and is conducted every three years.

PISA is designed to assess students' ability to apply their knowledge and skills to real-world situations. The assessment is not curriculum-based, but rather focuses on students' ability to think critically and solve problems.

PISA is one of the most widely used international assessments and is used by policymakers, educators, and researchers to track student achievement over time and to compare student achievement across countries.

The results of PISA are published in a series of reports that provide detailed information about students' performance in each of the three assessed domains. The reports also include information about students' backgrounds and attitudes towards learning.

PISA is a valuable tool for understanding student achievement and for improving educational outcomes. The assessment provides policymakers, educators, and researchers with the information they need to make informed decisions about how to best support students.