Before he moved over to his new home at Mother Jones, Kevin Drum revisited a topic at his old Washington Monthly blog that I too have raised before, to criticize reporters who say that there is “statistical dead heat” whenever the polls show the difference between voters preferences for two candidates fall within the margin of error.
In other words, if the polls show 46% for Obama and 43% for McCain with a 3% margin of error, then the race is reported as a “statistical tie” or some such thing, giving the impression that it is a toss-up as to who is ahead. This is simply not true.
Drum has consulted with two professors pf mathematics and statistics at California State University, Chico and they have provided the formulas that enabled him to prepare a handy little chart to tell you the actual chance that some one is ahead, even though the preferences fall within the margin of error.
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