Nate Silver of the New York Times writes about interpreting the current presidential polls while accounting for statistical variation (noise).  He zeros in on a poll by Public Policy Polling.  The poll was interpreted in some recent headlines as Obama losing African-American support in North Carolina.

The headlines don’t account for the larger statistical noise that is induced by a subgroup and fail to consider larger polls such as the Gallop Poll which tracks a sample of 3,500 weekly.