Here's the question Anthony Cody asked Bill Gates on Reddit.
Mr. Gates, I am a teacher recently retired after 24 years in the high poverty schools of Oakland, California.
Your foundation has decided that the variable that is the key to overcoming poverty in the US is the ability of our teachers to raise test scores. Differences between teachers account for less than 15% of the differences in student outcomes, research has shown.
You have stated that measuring things and setting goals has great power. Why not measure other factors that are known to contribute far more to student success? Things like rates of unplanned pregnancy, availability of preschool, equitable funding for schools, lead poisoning, access to libraries, poverty, nutrition, neighborhood violence?
Attention to any one of these things would yield better results than our obsession over test scores.
See here: http://blogs.edweek.org/teachers/living-in-dialogue/2013/02/an_open_letter_to_bill_gates_w.html