Exit Polls Will Give Good Idea About Race Results by 8 p.m.

Although initial early afternoon exit poll results will be released starting at 5 p.m., exit poll experts will be able to adjust their survey results by mid-evening to compensate for people who choose not to provide their answers to interviewers.

The so-called "non-response" bias occurs when people choose not to participate in interviews with survey takers.

Edison Media Research and Mitofsky International are conducting exit polling in 2008 for the National Election Pool (NEP), a consortium of media companies including ABC News, Associated Press, CBS News, CNN, Fox News, and NBC News.

"By about 8 or 9 p.m. we will have seen enough actual vote returns at the precinct level to be able to adjust for the non-response bias in several states," said Joe Lenski, Executive Vice President of Edison Media Research in an interview last week with Pew Research Center.

While initial exit poll results will be released to media firms who subscribe to an exit poll service starting at 5 p.m., they will be incomplete, containing only results of interviews with voters leaving polling places until the early afternoon.