> The quality of teachers really matters. In Canada, teaching generally requires a university degree in education or a university degree with additional education in teaching. Salaries are decent in most provinces. There are still lots of bad teachers out there. I can't imagine what it's like in places where standards and pay are lower. Perhaps we should put as much effort into developing better teachers as we do into developing better teaching methods.

This is a double edged sword, though. You have extremely knowledgeable people who can't teach because they have an actual degree in their subject matter but not in education. Also stuff like PE teachers teaching physics because they have the required education degree already and they can't find any physicists with them.