http://www.usatoday.com/news/opinion/story/2012-03-21/testing-isnt-teaching-W... Kevin Welner writes this opinion piece about the dangers of using test scores to measure teacher quality. Yes, a good teacher should be able to help students get higher scores, but when teaching is so much more than getting test scores, and measurement error leads us to uncertain results, it's irresponsible to put people's careers on the line and distort the purpose of school to do it.