First: Taking polls with different sampling criteria and averaging them is not a valid statistical technique. Sorry, but it just is not, because polls with different sampling techniques or cohorts are not measuring the same thing. Averaging them makes no more sense than averaging apples and bananas to get the average number of apples in your kitchen. This is why the RCP average is nonsense.
Second, the diagram is mostly, but not entirely correct. Likely voters ought to be -- but isn't quite -- a proper subset of registered voters. Discounting fraud, which is small but exists, would make likely voters and actual voters both proper subsets of registered voters. But it is still not the case that actual voters is a proper subset of likely voters. The CRUX of accuracy in presidential election polling now is entirely a matter of how to correctly determine if a likely voter will actually vote, AND if there are registered voters who will vote who are not captured by the "likely" formula.
The CRUX of accuracy in presidential election polling now is entirely a matter of how to correctly determine if a likely voter will actually vote, AND if there are registered voters who will vote who are not captured by the "likely" formula. So, Fred, if I understand you correctly the key to accurate polling is to measure intensity and to accurately size the "likely" voting group. I do not know that any poll tells me much about intensity-is this so?
I have a gut feeling without any empirical evidence to support my view that 2012 will look very much more like 2010 than previous presidential election cycles and that is because of an inchoate understanding that intensity is on the side of Republicans and normally uninvolved citizens not regarded to be likely voters will in fact turnout and support the Republicans.
Do I understand you to say that my suspicion, if proved correct in the event, will play a far more decisive role than normally accepted?
I also note that the chart showing the relative Democrat/Republican breakdown shows no consistent correlation in the size of the victory for other party. Can the intensity factor explain this?
