Yes, it matters who does the job. Good teachers have measurably better effects on students than bad ones. Here's one essay with a lot of statistics: http://www.

Yes, it matters who does the job. Good teachers have measurably better effects on students than bad ones. Here's one essay with a lot of statistics: http://www.nytimes.com/2012/01/12/opinion/kristof-the-value-of-teachers.html http://www.nytimes.com/2012/01/12/opinion/kristof-the-value-... . I also remember hearing a few years ago that a good teacher can teach about twice as much in a year as an average teacher, but I'm not sure if that's the same as the 40% number from this article or something else. The effect is an especially big deal in math, because it is so cumulative. One of the worst things that can happen to a student is to have a bad math experience (whether it's the teacher, the other kids in the class, or whatever) one year, and then have future teachers never go back and cover the same material. That leaves students with permanent gaps in their knowledge, which hurts them later on.