◼ The skewed polls issue and why it is important - Dean Chambers/examiner.com
The difference is the weighting and/or sampling of Democrats, Republicans and independents in each survey....
The recent Pew Research Poll showed Obama leading 48 percent to 43 percent based on a sample that over-sampled Democrats by 3.8 percent and under-sampled Republicans by 7.0 percent. Unskewed, this poll's data indicated Romney leading 54 percent to 44 percent....
The recent NY Times/CBS News poll showed Obama leading 49 percent to 46 percent based on a sample that over-sampled Democrats by 10.7 percent and under-sampled independents by 11.2 percent. Unskewed, this poll's data indicated Romney leading 51 percent to 44 percent....
The infamous CNN/ORC poll showed Obama leading by six percent, 52 percent to 46 percent, almost the margin by which he won in 2008. But the survey sample was doubly-skewed, over-sampling Democrats 17.1 percent and under-sampling independents 25.0 percent. Unskewed, the data from this poll would reveal a 53 percent to 45 percent Romney lead.
◼ Is the latest Washington Post/ABC poll skewed for Obama?
In this survey, the sampling is based on only 24 percent responding as Republicans, while Democrats were 33 percent, Independents were 36 and the remaining 7 percent responded otherwise. No serious observer of American politics or pollster believes that Republicans make up only 24 percent of the population. Is it precisely this under-sampling of Republicans, and proportional over-sampling of Democrats, that skews this survey.
◼ Poll Watch: Mitt Romney’s Leading in Swing States - Nice Deb
