Shame on the Iowa Des Moines Register and the Iowa Poll for peddling
nonsense from the latest iteration of the poll.
The newspaper and its pollster reported in great detail on their survey
about almost a dozen possible 2016 Republican presidential candidates, without
mentioning that the survey results are technically meaningless.
Selzer & Co., the pollster, interviewed 400 Republicans who “planned
to vote” in the June 3 primary in Iowa. Hardly a credible sample frame, for
starters….
Selzer reported the survey had a margin of error of plus/minus 4.9
percentage points.
OK, so here’s the up-front problem: nearly all of the different survey
results—for “favorability” and “most electable” and so on—for most of the 11
candidates are with the range of the margin of error, meaning that the only
honest interpretation of the findings is “we can’t say there’s any reliable difference
between the candidates.”
Technically, based on these poll findings, there are no obvious frontrunners. With
a margin of error of 4.9 points, any two results less than 9.9 percentage
points apart do not legitimately represent any real difference.
And by the way: the news release I saw made no mention of the computerized
statistical “weighting” that pollsters must do these days to even pretend that
they’re reporting results from a satisfactory random sample, which of course
they aren’t because no pollster can reach a true random sample these days. All
political survey results are adjusted and privately cooked by the pollsters to make
the results seem more reasonable—but the “weighting” makes them less reliable.
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