Finns ranked number one in reading comprehension and science, and third in problem solving. Finland's performance in math was second only to students in Hong Kong. This gave Finnish schools the highest overall score.
The study is part of the OECD's Programme for International Student Assessment. It tested 15-year-olds from 41 countries.
The PISA study also showed that while wealthier countries generally fared better, high spending does not equal high quality of education. The OECD mentioned that Finland had an excellent value for money, compared to big spenders like the United States which ranked consistently below the OECD average.
Although Finns are exceptionally good at math, it doesn't mean that they necessarily like the subject. Students' interest in math was the fourth-lowest of all the nations surveyed.
Consistency was a particular strong point in the Finnish school system. There are very few differences along geographical or social lines.