… Some pollsters and media organizations think the practice of averaging polls that survey different universes or are conducted using different methodologies is bunk. They warn that considering cheaper, less rigorous polling on the same plane as live-caller polls that randomly contact landline and cell-phone respondents allows the averages to be improperly influenced by less accurate surveys. …
But others, including the poll aggregators themselves, maintain that averaging polls, or using poll results as part of a predictive model, produces a more accurate forecast than considering any one individual poll. …
Ultimately, this is a debate that also goes beyond the statistical questions about averaging polls. It touches on the nature of horse-race journalism and the way in which we cover campaigns. [cont.]
Steven Shepard, National Journal