When:
Five-yearly assessment since 2001.

Who:
Year 5 students.

What:
Reading literacy achievement and background information.

How:
Conducted under the auspices of the IEA; managed internationally by the International Study Centre at Boston College; and nationally by the Ministry of Education.

Where:
From 35 countries in 2001 to 57 countries and 8 benchmarking participants in 2020-2022.

The Progress in International Reading Literacy Study (PIRLS) is an educational research study on children's reading literacy achievement conducted in countries and jurisdictions around the world. The first study was conducted in 35 countries during 2001. Administered every five years, the study is designed to measure trends in the achievement of middle primary school students as well as providing countries and jurisdictions with a snapshot of achievement at each cycle. The study involves New Zealand's Year 5 students.

As well as assessing students, PIRLS also collects background information, using questionnaires, from the students, their parents/caregivers, their reading teachers, and from the principals of the schools at which they attend.

Results from the fifth cycle of PIRLS, known internationally as PIRLS 2021, were released on 16 May 2023. Development work for the sixth cycle, PIRLS 2026, is underway, with the field trial scheduled for March 2025 and the main study in November 2026.

PIRLS is conducted under the auspices of the International Association for the Evaluation of Educational Achievement (IEA), which is an independent international co-operative of national research institutions and government agencies. In New Zealand, the Ministry of Education’s Educational Measurement and Assessment Team manages the implementation of the school-based international studies, including PIRLS.