|Education system||Cycle I||Cycle II|
|Korea, Republic of||●||○|
|United Kingdom (England)||●||○|
|United Kingdom (Northern Ireland)||●|
|United States||●||See note2||●3||○|
● = Indicates participation in particular assessment with results reported or forthcoming.
○ = Indicates participation in particular assessment but results either not reported or reported separately, typically due to sampling problems, response rate problems, or other procedural problems with the data.
1 The Republic of Cyprus is recognized by all members of the United Nations except Turkey. Until a lasting and equitable solution is found within the context of the United Nations, Turkey will maintain the same position toward Cyprus. The information in PIAAC relates to the area under the effective control of the Government of the Republic of Cyprus.
2 In 2014, the United States conducted a second round of national data collection, known as the National Supplement to the Main Study. The U.S. Round 2 data collection was not administered to a nationally representative sample; instead, it was designed to enhance and expand the U.S. Round 1 data. Thus, U.S. Round 2 data are reported only as part of the combined 2012/2014 U.S. PIAAC dataset.
3 In 2017, the United States conducted a third round of national data collection with a nationally representative sample of U.S. adults, providing a comparison to the 2012/2014 data and supporting the calculation of state- and county-level estimates.
4 Overall, 39 countries participated in Cycle I of PIAAC, including 25 countries in Round 1 (2012), 9 additional countries in Round 2 (2015), and 5 more countries in Round 3 (2017). Although the United States conducted multiple data collections during Cycle I, it only counts once toward the total number of participating countries in Cycle I.
NOTE: OECD member countries are bolded. Subnational education systems are italicized.
SOURCE: Organization for Economic Cooperation and Development (OECD), Program for the International Assessment of Adult Competencies (PIAAC).