I'm surprised at the comments here. Seems that nearly everyone disagrees with the blog? Is Bill Gates such a saint among the HN crowd that we ignore statistics for him?
Seems pretty clear that Gates' study presents the data in a very misleading manner to make a very weak correlation look like a very strong correlation.
You criticize a short blog post for something that is not done in the Gates publication. Do you have some bias, perhaps? Why does Gates not even give us a scatter plot, let alone a correlation coefficient? This is the critical point raised by the blog.
I never said they don't report "quite a few statistics". I said they don't report this one specific particularly important statistic, and instead obscure it behind a ridiculous averaging procedure. This was either done because they are incompetent or because they are purposely trying to mislead. That's the whole point of TFA.
Also, see this blog for some more discussion along the same lines: http://ed2worlds.blogspot.com/2013/01/gates-foundation-waste...
Seems pretty clear that Gates' study presents the data in a very misleading manner to make a very weak correlation look like a very strong correlation.