CNN's explanation--How they project the winner

(CNN) -- To project primaries and caucuses, CNN and its election experts use scientific statistical procedures to make estimates of the final vote count in each race. CNN will broadcast a projected winner only after an extensive review of data from a number of sources.

CNN editorial policy strictly prohibits reporting winners or characterizing the outcome of a statewide contest in any state before all the polls are scheduled to close in every precinct in that state.

CNN will receive information from the following sources:

http://www.cnn.com/2008/P...