from Amazon
Friday, July 16, 2010
And yet more HR derby hangover effects
Matt takes a look, and he does it along the lines of what MGL did for the hot/cold streaks in The Book: focus on a very narrow time frame, on the idea that if something were to happen, it would be most noticeable immediately.
As you’d expect, little to no change. The article’s value is in its process, not in its findings (or lack of). People who read the article and say they learn nothing, well, you missed learning something.
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I also want to point out, as I always do, that just because something is statistically significant, it does NOT mean that that particular observed difference is the estimated true difference. All we know is that we estimate that we have a true non-zero difference.
In short, it tells you that there is a difference, but it says nothing about how much the observed difference is the true difference (other than the higher the t-test, the more the difference is real).