1 Different countries administered PIAAC, IALS, and ALL in different years. For the most part, all of these studies only conducted one round of data collection in each country to date. However, PIAAC has been administered multiple times in some countries, including the United States, in order to expand their original samples. Some of the data, particularly estimates relating to literacy, are comparable across IALS, ALL and PIAAC.
2 For one or multiple international studies, the following education systems' results were either not reported or reported separately, typically due to sampling, response rates, or other procedural problems with the data: Argentina and Philippines for TIMSS 1995 (8th-grade); Argentina and England-GBR for TIMSS 2003 (8th-grade); Argentina, Kazakhstan, and Malaysia for PISA 2015; Armenia for TIMSS 2015 (4th- and 8th-grade); Buenos Aires-ARG, Denmark, Hong Kong-CHN, Netherlands, and Switzerland for ICILS 2013; Indonesia, Italy, and Mexico for TIMSS 1995 (4th- and 8th-grade); Mongolia for TIMSS 2007 (4th-grade); Mongolia and Morocco for TIMSS 2007 (8th-grade); Russian Federation for PIAAC 2012; United States for TALIS 2013; and Yemen for TIMSS 2003 (4th-grade).
3 3B-S-J-G (China) refers to the four PISA participating China provinces: Beijing, Shanghai, Jiangsu, and Guangdong. Chinese provinces also participated in PISA 2018.
NOTE: OECD member countries are bolded. Subnational education systems are italicized.
SOURCE: International Association for the Evaluation of Educational Achievement (IEA): Civic Education Study (CivEd), International Civic and Citizenship Study (ICCS), International Computer and Information Literacy Study (ICILS), Progress in International Reading Literacy Study (PIRLS), and Trends in International Mathematics and Science Study (TIMSS). Organization for Economic Cooperation and Development (OECD): Adult Literacy and Lifeskills Survey (ALL), International Adult Literacy Survey (IALS), Program for the International Assessment of Adults Competencies (PIAAC), Program for International Student Assessment (PISA), and Teaching and Learning International Survey (TALIS).