While Businessweek had an interesting infographic on the difference between correlation and causation, xkcd provides a different take on the logical fallacy of cum hoc ergo propter hoc (correlation proves causation).
Image by xkcd
In other words, correlation enables prediction whereas causation enables explanation. Correlation denotes the strength of a relationship between two variables, while causation requires correlation of cause and effect, temporal precedence and rejection of alternative hypotheses.
via Correlation versus Causation (cum hoc ergo propter hoc) « A little bit of this, a little bit of that.
Edit: Don’t forget the mouse-over text.
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