How much does instruction time matter? Comparing country-level data on class time with PISA 2012 data on learning outcomes for mathematics does not seem to support the hypothesis that more instruction time leads to better student learning outcomes.
It actually goes the other way: the 10 countries with the highest instruction time have a mean PISA score for mathematics, which is 20 score-points below that of the 10 countries with the lowest amount of instruction time.
More than 2 700 hours of instruction do not seem to make a difference in learning outcomes.
