International assessment participation
International Assessment Participation by Country: PISA, TIMSS, PIRLS and ICILS
Country, economy and education-system participation across PISA 2025, TIMSS 2023, PIRLS 2026 and ICILS 2023. Active assessment cycles, published-result cycles, constituent systems, regional samples and benchmarking entities are identified separately.
Participation Statistics
Organizer totals and normalized roster calculations use the selected official assessment cycles.
PISA 2025
91
Countries and economies
TIMSS 2023
71
Education systems listed
PIRLS 2026
62
Official stated total; 63 names are enumerated
ICILS 2023
35
Participating entities
Listed in all four
23
Exact normalized entity matches
Combined union
113
National and non-national entries
Participation Coverage Across Selected Cycles
The organizer totals use different reporting units and should not be treated as sovereign-country counts.
Listed Participants by Assessment
Countries, economies or education systems in the selected official rosters
PISA 2025 and PIRLS 2026 are active cycles. TIMSS 2023 and ICILS 2023 have published international results.
Chart analysis
- PISA 2025 has the largest stated roster at 91 countries and economies.
- TIMSS 2023 lists 71 systems across Grade 4, Grade 8 or both grade levels.
- PIRLS 2026 states 62 systems, while the official roster enumerates 63 names.
- ICILS 2023 includes 35 participating entities.
- The four totals are not directly additive because national systems, constituent systems and benchmarking entities can overlap.
Country and Education-System Participation Table
“Not listed” means that the entity does not appear in the selected cycle roster. It does not describe participation in earlier cycles.
| Country or system | Entity type | PISA 2025 | TIMSS 2023 | PIRLS 2026 | ICILS 2023 | Count |
|---|---|---|---|---|---|---|
| Albania | National | Listed | Listed | Listed | Not listed | 3 |
| Argentina | National | Listed | Not listed | Not listed | Not listed | 1 |
| Armenia | National | Listed | Listed | Not listed | Not listed | 2 |
| Australia | National | Listed | Listed | Listed | Not listed | 3 |
| Austria | National | Listed | Listed | Listed | Listed | 4 |
| Azerbaijan | National | Listed | Listed | Listed | Listed | 4 |
| Bahrain | National | Not listed | Listed | Listed | Not listed | 2 |
| Belgium | National | Listed | Not listed | Not listed | Not listed | 1 |
| Belgium, Flemish | Constituent | Not listed | Listed | Listed | Listed | 3 |
| Belgium, French | Constituent | Not listed | Listed | Listed | Not listed | 2 |
| Bosnia and Herzegovina | National | Not listed | Listed | Not listed | Listed | 2 |
| Brazil | National | Listed | Listed | Listed | Not listed | 3 |
| Brunei Darussalam | National | Listed | Not listed | Not listed | Not listed | 1 |
| Bulgaria | National | Listed | Listed | Listed | Not listed | 3 |
| Cambodia | National | Listed | Not listed | Not listed | Not listed | 1 |
| Canada | National | Listed | Listed | Listed | Not listed | 3 |
| Canada (Ontario) | Benchmark | Not listed | Listed | Listed | Not listed | 2 |
| Canada (Quebec) | Benchmark | Not listed | Listed | Listed | Not listed | 2 |
| Chile | National | Listed | Listed | Not listed | Listed | 3 |
| China | National | Listed | Not listed | Not listed | Not listed | 1 |
| Chinese Taipei | Economy | Listed | Listed | Listed | Listed | 4 |
| Colombia | National | Listed | Not listed | Not listed | Not listed | 1 |
| Costa Rica | National | Listed | Not listed | Not listed | Not listed | 1 |
| Croatia | National | Listed | Not listed | Not listed | Listed | 2 |
| Cyprus | National | Not listed | Listed | Listed | Listed | 3 |
| Czechia | National | Listed | Listed | Listed | Listed | 4 |
| Côte d’Ivoire | National | Not listed | Listed | Not listed | Not listed | 1 |
| Denmark | National | Listed | Listed | Listed | Listed | 4 |
| Dominican Republic | National | Listed | Not listed | Not listed | Not listed | 1 |
| Ecuador | National | Listed | Not listed | Not listed | Not listed | 1 |
| Egypt | National | Listed | Not listed | Not listed | Not listed | 1 |
| El Salvador | National | Listed | Not listed | Not listed | Not listed | 1 |
| England | Constituent | Not listed | Listed | Listed | Not listed | 2 |
| Estonia | National | Listed | Not listed | Not listed | Not listed | 1 |
| Finland | National | Listed | Listed | Listed | Listed | 4 |
| France | National | Listed | Listed | Listed | Listed | 4 |
| Georgia | National | Listed | Listed | Listed | Not listed | 3 |
| Germany | National | Listed | Listed | Listed | Listed | 4 |
| Germany (North Rhine-Westphalia) | Benchmark | Not listed | Not listed | Not listed | Listed | 1 |
| Greece | National | Listed | Not listed | Not listed | Listed | 2 |
| Guatemala | National | Listed | Not listed | Not listed | Not listed | 1 |
| Hong Kong | Economy | Listed | Listed | Listed | Not listed | 3 |
| Hungary | National | Listed | Listed | Listed | Listed | 4 |
| Iceland | National | Listed | Not listed | Not listed | Not listed | 1 |
| Indonesia | National | Listed | Not listed | Not listed | Not listed | 1 |
| Iran | National | Not listed | Listed | Listed | Not listed | 2 |
| Iraq | National | Not listed | Listed | Not listed | Not listed | 1 |
| Ireland | National | Listed | Listed | Listed | Not listed | 3 |
| Israel | National | Listed | Listed | Listed | Not listed | 3 |
| Italy | National | Listed | Listed | Listed | Listed | 4 |
| Japan | National | Listed | Listed | Not listed | Not listed | 2 |
| Jordan | National | Listed | Listed | Listed | Not listed | 3 |
| Kazakhstan | National | Listed | Listed | Listed | Listed | 4 |
| Kenya | National | Listed | Not listed | Not listed | Not listed | 1 |
| Korea, Republic of | National | Listed | Listed | Listed | Listed | 4 |
| Kosovo | National | Listed | Listed | Not listed | Listed | 3 |
| Kurdistan Region of Iraq | Regional sample | Listed | Listed | Not listed | Not listed | 2 |
| Kuwait | National | Not listed | Listed | Listed | Not listed | 2 |
| Kyrgyzstan | National | Listed | Not listed | Not listed | Not listed | 1 |
| Latvia | National | Listed | Listed | Listed | Listed | 4 |
| Lebanon | National | Listed | Not listed | Not listed | Not listed | 1 |
| Lithuania | National | Listed | Listed | Listed | Not listed | 3 |
| Luxembourg | National | Listed | Not listed | Not listed | Listed | 2 |
| Macao | Economy | Listed | Listed | Listed | Not listed | 3 |
| Malaysia | National | Listed | Listed | Not listed | Not listed | 2 |
| Malta | National | Listed | Listed | Listed | Listed | 4 |
| Mauritius | National | Listed | Not listed | Not listed | Not listed | 1 |
| Mexico | National | Listed | Not listed | Not listed | Not listed | 1 |
| Moldova | National | Listed | Not listed | Not listed | Not listed | 1 |
| Mongolia | National | Listed | Not listed | Not listed | Not listed | 1 |
| Montenegro | National | Listed | Listed | Listed | Not listed | 3 |
| Morocco | National | Listed | Listed | Listed | Not listed | 3 |
| Netherlands | National | Listed | Listed | Listed | Listed | 4 |
| New Zealand | National | Listed | Listed | Listed | Not listed | 3 |
| North Macedonia | National | Listed | Listed | Listed | Not listed | 3 |
| Northern Ireland | Constituent | Not listed | Not listed | Listed | Not listed | 1 |
| Norway | National | Listed | Listed | Listed | Listed | 4 |
| Oman | National | Not listed | Listed | Listed | Listed | 3 |
| Palestine | National | Listed | Listed | Not listed | Not listed | 2 |
| Paraguay | National | Listed | Not listed | Not listed | Not listed | 1 |
| Peru | National | Listed | Not listed | Not listed | Not listed | 1 |
| Philippines | National | Listed | Not listed | Not listed | Not listed | 1 |
| Poland | National | Listed | Listed | Listed | Not listed | 3 |
| Portugal | National | Listed | Listed | Listed | Listed | 4 |
| Qatar | National | Listed | Listed | Listed | Not listed | 3 |
| Romania | National | Listed | Listed | Listed | Listed | 4 |
| Rwanda | National | Listed | Not listed | Not listed | Not listed | 1 |
| Saudi Arabia | National | Listed | Listed | Listed | Not listed | 3 |
| Scotland | Constituent | Not listed | Not listed | Listed | Not listed | 1 |
| Serbia | National | Listed | Listed | Listed | Listed | 4 |
| Singapore | National | Listed | Listed | Listed | Not listed | 3 |
| Slovak Republic | National | Listed | Listed | Listed | Listed | 4 |
| Slovenia | National | Listed | Listed | Listed | Listed | 4 |
| South Africa | National | Not listed | Listed | Listed | Not listed | 2 |
| Spain | National | Listed | Listed | Listed | Listed | 4 |
| Sweden | National | Listed | Listed | Listed | Listed | 4 |
| Switzerland | National | Listed | Not listed | Not listed | Not listed | 1 |
| Tajikistan | National | Not listed | Not listed | Listed | Not listed | 1 |
| Tajikistan (Dushanbe) | Regional sample | Listed | Not listed | Not listed | Not listed | 1 |
| Thailand | National | Listed | Not listed | Not listed | Not listed | 1 |
| Türkiye | National | Listed | Listed | Not listed | Not listed | 2 |
| Ukraine | National | Listed | Not listed | Not listed | Not listed | 1 |
| United Arab Emirates | National | Listed | Listed | Listed | Not listed | 3 |
| United Arab Emirates (Abu Dhabi) | Benchmark | Not listed | Listed | Listed | Not listed | 2 |
| United Arab Emirates (Dubai) | Benchmark | Not listed | Listed | Listed | Not listed | 2 |
| United Arab Emirates (Sharjah) | Benchmark | Not listed | Listed | Listed | Not listed | 2 |
| United Kingdom | National | Listed | Not listed | Not listed | Not listed | 1 |
| United States | National | Listed | Listed | Not listed | Listed | 3 |
| Uruguay | National | Listed | Not listed | Not listed | Listed | 2 |
| Uzbekistan | National | Listed | Listed | Listed | Not listed | 3 |
| Viet Nam | National | Listed | Not listed | Not listed | Not listed | 1 |
| Wales | Constituent | Not listed | Not listed | Listed | Not listed | 1 |
| Zambia | National | Listed | Not listed | Not listed | Not listed | 1 |
Table analysis
- 23 entries appear in all four selected rosters.
- 28 entries appear in three assessments, 22 appear in two and 40 appear in one.
- The union contains 96 national entries, six constituent systems, six benchmarking entities, three economies and two regional samples.
- Austria, Azerbaijan, Chinese Taipei, Czechia, Denmark, Finland, France, Germany, Hungary, Italy, Kazakhstan, Korea, Latvia, Malta, the Netherlands, Norway, Portugal, Romania, Serbia, the Slovak Republic, Slovenia, Spain and Sweden appear in all four rosters.
- PISA records the United Kingdom as one participant, while IEA rosters may report England, Scotland, Wales or Northern Ireland separately.
- Canada, Germany and the United Arab Emirates have separate subnational benchmarking entries in at least one selected IEA roster.
- TIMSS participation does not establish whether a system assessed Grade 4, Grade 8 or both.
- ICILS participation does not establish participation in the optional computational thinking module.
- Active-cycle participation does not indicate that internationally comparable results have already been released.
Assessment Coverage Overlap
The overlap calculation uses normalized entries while retaining distinct geographic scopes.
Number of Assessments per Listed Entity
Distribution across the four selected assessment rosters
The calculation describes roster overlap, not score availability or student-level assessment overlap.
Assessment analysis
- 40 entries occur in only one of the four selected rosters.
- 51 entries occur in at least three rosters.
- The four-assessment group contains 23 normalized entries.
- A national entry and its benchmarking region are counted separately when the official geographic scopes differ.
What Each Assessment Covers
Participation cannot be interpreted without the target population, assessed domains and cycle stage.
| Assessment | Organizer | Target population | Main domains | Selected cycle status |
|---|---|---|---|---|
| PISA 2025 | OECD | Students aged 15 | Science, mathematics and reading; optional or innovative domains vary | Active cycle; initial results scheduled for 8 September 2026 |
| TIMSS 2023 | IEA | Grade 4 and Grade 8 | Mathematics and science | International results published |
| PIRLS 2026 | IEA | Grade 4 or equivalent reading stage | Reading comprehension and literacy | Active cycle; results planned for December 2027 |
| ICILS 2023 | IEA | Usually Grade 8 | Computer and information literacy; optional computational thinking | International results published |
Assessment analysis
- PISA is age-based, while TIMSS, PIRLS and ICILS primarily use grade-based target populations.
- TIMSS separates Grade 4 and Grade 8 reporting; a combined roster does not reveal grade coverage.
- PIRLS focuses on reading at the fourth-grade stage and does not measure the same population as PISA.
- ICILS measures digital competencies rather than reading, mathematics or science achievement.
- Participation in multiple programs does not mean that the same students were tested.
Entity Labels and Geographic Scope
Official program labels were preserved where different education systems are reported separately.
| Reported entry | Parent geography | Type | Counting treatment |
|---|---|---|---|
| Ontario | Canada | Benchmarking entity | Retained separately from Canada |
| Quebec | Canada | Benchmarking entity | Retained separately from Canada |
| North Rhine-Westphalia | Germany | Benchmarking entity | Retained separately from Germany |
| Abu Dhabi | United Arab Emirates | Benchmarking entity | Retained separately from the national entry |
| Dubai | United Arab Emirates | Benchmarking entity | Retained separately from the national entry |
| Sharjah | United Arab Emirates | Benchmarking entity | Retained separately from the national entry |
| England | United Kingdom | Constituent system | Kept separate from the PISA United Kingdom entry |
| Scotland | United Kingdom | Constituent system | Kept separate from the PISA United Kingdom entry |
| Wales | United Kingdom | Constituent system | Kept separate from the PISA United Kingdom entry |
| Northern Ireland | United Kingdom | Constituent system | Kept separate from the PISA United Kingdom entry |
| Belgium, Flemish | Belgium | Constituent system | Kept separate from the PISA Belgium entry |
| Belgium, French | Belgium | Constituent system | Kept separate from the PISA Belgium entry |
| Tajikistan (Dushanbe) | Tajikistan | Regional sample | Kept separate from the national PIRLS entry |
| Kurdistan Region of Iraq | Iraq | Regional sample | Kept separate because the geographic scope differs |
Source-year analysis
- Subnational entries are valid assessment participants but are not separate sovereign countries.
- National and subnational records must not be added together when calculating country coverage.
- The United Kingdom and Belgium illustrate how OECD and IEA reporting units can differ.
- Tajikistan and Tajikistan (Dushanbe) remain separate because their assessment scopes are not equivalent.
PISA Participation by Assessment Cycle
The OECD participation workbook provides a long-run roster series. The 2000+ and 2009+ extensions are combined with their associated cycles.
PISA Roster Size, 2000–2025
Countries and economies recorded in the OECD participation workbook
The workbook roster increases from 42 entries in the combined first cycle to 91 in 2025.
Trend analysis
- The combined 2000 and 2000+ cycle contains 42 participants.
- The combined 2009 and 2009+ cycle reaches 74.
- The workbook records 78 participants in 2018 and 80 in 2022.
- The PISA 2025 roster reaches 91, 49 more than the combined first cycle.
- OECD PISA 2022 publications describe 81 participants, while the current participation workbook yields 80 entries for that cycle.
| Cycle | Roster count | Change | Status note |
|---|---|---|---|
| 2000 / 2000+ | 42 | Starting cycle | Combined main and extended administrations |
| 2003 | 42 | 0 | Standard assessment cycle |
| 2006 | 57 | +15 | Standard assessment cycle |
| 2009 / 2009+ | 74 | +17 | Combined main and extended administrations |
| 2012 | 64 | −10 | Standard assessment cycle |
| 2015 | 71 | +7 | Standard assessment cycle |
| 2018 | 78 | +7 | Standard assessment cycle |
| 2022 | 80 | +2 | Count produced from the current participation workbook |
| 2025 | 91 | +11 | Active cycle; initial results scheduled for 8 September 2026 |
Trend analysis
- The largest cycle-to-cycle increase in the table is 17 entries between 2006 and the combined 2009 cycle.
- The combined roster declined by 10 between the 2009 and 2012 cycles.
- The 2025 roster is 13 entries larger than the 2018 roster.
- Cycle counts describe assessment participation, not tested-student totals or average scores.
- PISA 2025 results are not part of the published achievement-score series before their scheduled release.
Participation Interpretation Notes
Roster presence alone does not establish comparable results across every listed entity.
Cycle stage
PISA 2025 and PIRLS 2026 are active cycles. TIMSS 2023 and ICILS 2023 have published international results.
Participation unit
OECD PISA commonly reports countries and economies. IEA may report national, constituent and benchmarking systems separately.
TIMSS grade scope
TIMSS covers Grade 4 and Grade 8. A roster flag does not identify whether one or both grade levels were assessed.
ICILS module scope
Computer and information literacy is the main domain. Computational thinking is optional and requires a separate participation check.
Roster and result totals
The TIMSS 2023 cycle roster lists 71 systems. Published result summaries use different totals when countries and benchmarking entities are reported separately.
Future-cycle interest
IEA lists 34 systems as interested in ICILS 2028. An expression of interest is not coded as confirmed participation.
Source and Methodology
PISA participation source OECD PISA participation records and the official cycle workbook linked from that record.
PISA cycle status OECD Programme for International Student Assessment.
TIMSS source IEA TIMSS 2023.
PIRLS source IEA PIRLS 2026.
ICILS source IEA ICILS 2023.
ICILS 2028 status IEA interested-entity roster.
Coverage Entries appearing in at least one of the four selected official rosters.
Participation unit Country, economy, national education system, constituent system, benchmarking entity or regional sample.
Missing status “Not listed” means absent from the selected cycle roster. It is not a statement about all historical cycles.
Name normalization Obvious variants such as Korea and Republic of Korea were aligned. Different geographic units remain separate.
Calculated fields The 113-entry union, assessment-count distribution and entity-type totals are roster-based calculations.
PISA historical rule The 2000 and 2000+ records are combined, as are 2009 and 2009+.
Rounding Participant counts and calculated roster totals are shown as whole entries without rounding.
Result availability Participation in an active cycle is reported separately from the publication of international results.
The PIRLS 2026 source states 62 participating systems but enumerates 63 names. The stated total is retained in the headline chart, while every enumerated system is retained in the country table. The current OECD participation workbook produces 80 PISA 2022 entries, while OECD result publications describe 81 participating countries and economies; the discrepancy is disclosed without altering the official workbook records.
Methodological Safety Note
Participation is not a score, rank or measure of education quality. Direct comparisons require the same assessment cycle, target population, grade or age group, subject domain, reporting status and acceptable sampling coverage. National records, constituent systems and benchmarking entities must not be added together as separate sovereign countries.