Northern Ireland and England are in the top 10 of the world's best primary school readers in global rankings. The Progress in International Reading Literacy Study - known as PIRLS - shows Northern Ireland in joint sixth place, with England in joint eighth.
Both Northern Ireland and England have reached their highest point scores in reading tests taken in 50 countries. Russia takes the top place - the first time it has headed an international education league table. The Republic of Ireland, in fourth, is second only to Russia among European countries.
Geoff Barton, leader of the ASCL head teachers' union, praised the work of schools in England and Northern Ireland and said the results reflected "the huge focus that schools have placed on the teaching of reading over the course of many years".
The tests taken by almost 320,000 10-year-olds around the world, show Northern Ireland's pupils as among the highest achievers, ranked joint sixth with Poland. The result puts them only marginally behind long-standing high achievers such as Finland.
England was ranked joint eighth, alongside Norway and Taiwan, and England's school standards minister Nick Gibb hailed the positive impact of the phonics system of learning to read. This is a much higher ranking than in the international Pisa tests for secondary school pupils, run by the OECD, in which England is not in the top 20 for reading or maths.
The Top 10 Countries for primary reading are:
1. Russia
2. Singapore
3. Hong Kong
4. Republic of Ireland
5. Finland
6. Poland
= Northern Ireland
8. Norway
= Taiwan
= England
Comparisons with the last rankings from five years ago depend on which measures are used, says the International Association for the Evaluation of Educational Achievement (IEA), which runs the PIRLS tests with Boston College in the US.
Five years ago, the IEA says England was ranked 11th, but as there was no statistical significant difference with US, Denmark, Croatia, Chinese Taipei, and Ireland this "could be interpreted as a joint sixth ranking".
