… For more than a quarter-century, no matter which channel you were watching, much of that punditry ultimately derived from the same source: a nationwide survey of voters as they left their local polling places. …
But on election night 2018, there will be an additional source of data on who voted and why, developed by The Associated Press, Fox News and NORC at the University of Chicago and based on a very different methodology. That means that depending on where you go for election news, you may get a somewhat different portrait of this year’s electorate. CONT.
Drew DeSilver, Pew