> Last result showed a break from that Correction: The last two results. > many students which could have been expected to test poorly were dissuaded from par

> Last result showed a break from that Correction: The last two results. > many students which could have been expected to test poorly were dissuaded from participating. So the result from that year is in question You mean newly arrived immigrants. They would greatly decrease the results depending on how many were excluded, yes, but PISA makes a distinction between immigrants and natives anyway so just look at the natives results and you still see a strong positive trend. Also you could argue that immigrant performance isn't a good indicator of the school system of a country, only an indicator of what kind of immigrants they take in. So the only real number from PISA is actually the performance of students who grew up there and got their entire education in the country.