The reaction from many performance pay advocates to the Nashville evaluation released last week has been that the study is relatively meaningless (see here and here for examples). The general interpretation: The results show that the pay bonuses do not improve student achievement, but short-term test score gains are not the "true purpose" of these incentive programs. What they are really supposed to improve, so the line goes, is the quality of people who pursue teaching as a career, as well as their retention rates.
While I disagree that the findings are not important (they are, if for no other reason than they discredit the idea that teachers are holding their effort hostage to more money), I am sympathetic towards the view that the study didn’t tackle the big issues. Attracting the best possible people into the profession – and keeping them there – are much more meaningful goals than short-term test score gains, and they are not addressed in this study (though some results for retention are reported).
But this argument also begs a few important questions that I hope we can answer before the Nashville study fades into evaluation oblivion. I have three of them.