This is a short post because I’m on field trip in rural texas, another post with graph and explanation will be up soon.
In this statement, Research 2000 head Del Ali seems to state that he manually altered his polling data, though it’s hard to tell from the muddled language:
Yes we weight heavily and I will, using the margin of error adjust the top line and when adjusted under my discretion as both a pollster and social scientist, therefore all sub groups must be adjusted as well.
He also seems to say that this is common among pollsters:
I challenge anyone to then look at comparable data from other firms, not one or two but many others.
This is actually a very good point. In political polling especially, there seems to be an almost deliberate murkiness about methods. I think this is because many polls may not be actual data reported directly from polls, but rather estimations computed using outside information and only partially based on the polling sample.
While there is nothing wrong with estimation as opposed to raw sampling, it is important that a clear distinction be made between the two.