Why the polls failed

Name: Why the polls failed
Uploaded: 2016-11-12T17:01:09+00:00
Description: Columbia statistics professor Gelman explains why even last-minute polls have too wide a margin of error to be considered accurate.

Collected by CNN on Nov 12, 2016

Columbia statistics professor Gelman explains why even last-minute polls have too wide a margin of error to be considered accurate.

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