Not-in-School 15YOs distort Australian position on the PISA league table
The SOS Brief demonstrates that there are significant differences in the proportion in school even among developed countries which influence test scores and rankings.
For example, the high ranking countries of Vietnam, four Chinese cities and provinces and the UK drop out of the top 20 countries when test scores are adjusted for the proportion of 15-year-olds not in school.
The sample of Vietnam students participating in PISA was taken from only 48.5% of Vietnam’s 15-year-olds compared to Australia’s coverage of 90.6%. In the case of the four Chinese cities and provinces, the sample covered only 63.9%. Vietnam and the Chinese cities and provinces scored significantly higher than Australia on mean test scores. However, when account is taken of their low proportion of 15-year-olds in school their test scores and ranking drop far below that of Australia. Vietnam drops from 8th to between 35th and 40th, while the four Chinese cities and provinces drop from 10th to around 50th.
The analysis demonstrates that the proportion of 15-year-olds in schools can have a very large impact on country/city test scores and international rankings. A country, region or city with high test scores can hardly be considered a successful education performer if a large proportion of its 15-year-olds are not in education. The OECD should consider not including countries/regions/cities with a high proportion of 15-year-olds not in school in its international rankings because they can significantly distort the rankings and make them highly misleading.