1. Additional participants in previous cycles were Azerbaijan,
Himlichal Pradesh-India, Kyrgyzstan, Liechtenstein, Mauritius,
Miranda-Venezuela, Panama, Serbia, Tamil Nadu-India
2. In PISA 2015, the People’s Republic of China fielded four provinces compared to one (Shanghai) in previous rounds. The four provinces are Beijing, Shanghai, Jiangsu and Guangdong
3. Although the four countries joined the OECD in 2010, they were included as OECD members in the PISA reports for the 2009 round. Latvia was also included for 2015.
4. These are confidence intervals where we can be 95 per cent certain the “true” value lies. Where the intervals overlap, for example between Scotland and the OECD average, we cannot be sure that the true values are different.
5. Those OECD member states other than the United Kingdom
6. One state, Latvia, has joined the OECD since the previous PISA round in 2012. Although they experienced a decline in their science score between 2012 and 2015, this is not likely to have had a material effect on the overall average.
7. The OECD average for ESCS is roughly zero - with one point in ESCS representing a standard deviation away from the average.
8. Note this is a revision compared to previous reports (which estimated 40 points being equivalent to a year’s schooling), as a result of more recent research. Further details are set in Chapter 2 of Volume I of the international OECD report
9. The chart is not adjusted for constant OECD membership
10. Not significantly
11. The chart is not adjusted for constant OECD membership.