The Progress in International Reading Literacy Study (PIRLS) is an international assessment and research project designed to measure reading achievement at the fourth-grade level, as well as school and teacher practices related to instruction. Fourth-grade students complete a reading assessment and questionnaire that addresses students’ attitudes toward reading and their reading habits. In addition, questionnaires are given to students’ teachers and school principals to gather information about students’ school experiences in developing reading literacy. Since 2001, PIRLS has been administered every 5 years, with the United States participating in all past assessments. PIRLS is sponsored by the International Association for the Evaluation of Educational Achievement (IEA) and conducted in the United States by the National Center for Education Statistics (NCES).Go to Overview to learn more about PIRLS.