Education Funding: the Null Hypothesis

It's hard to believe that more money doesn't produce better results. It's hard to believe the graphs that accompany Evaluating the Null Hypothesis in Education | askblog

there is no clear correlation between funding and school average performance; for a given level of funding, there is significant variation in performance the calculated correlation coefficient between the two variables was less than 0.1. In our view, this suggests that the level of funding, per se, is almost irrelevant as a predictor of performance.

Not absolutely irrelevant; only almost.
Or then again, maybe not.