Get Political Wire by Email:

September 25, 2009

Pollster Cooking the Books?

Last night, we noted we would no longer report polling results from Strategic Vision due to substantial questions raised about their methodology and transparency.

Meanwhile, Nate Silver found that certain statistical properties of the results reported by Strategic Vision "suggest, perhaps strongly, the possibility of fraud, although they certainly do not prove it and further investigation will be required."

Noting that "human beings are really bad at randomization," Silver examines past polling results from the firm and find "this data is not random. It's not close to random. It's not close to close. Which brings up the other possibility: Strategic Vision is cooking the books. And whoever is doing so is doing a pretty sloppy job. They'd seem to have a strong, unconscious preference for numbers ending in '7', for instance, as opposed to those ending in '6'. They tend to go with round numbers that end in '5' or '0' slightly too often. And they much prefer numbers with high trailing digits like 49 and 38 to those with low ones like 51 and 42."

"I haven't really seen anyone approach polling data like this before, and I certainly haven't done so myself. So, we cannot rule out the possibility that there is some mathematical rationale for this that I haven't thought of. But it looks really, really bad. There is a substantial possibility -- far from a certainty -- that much of Strategic Vision's polling over the past several years has been forged."


Political Wire Podcast Engaging conversations about elections and the political issues of the day. Subscribe via iTunes or RSS to get episodes automatically downloaded.