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Thursday, April 1, 2010

A Problematic Poll

Our chapteron public opinion and participation urges readers to look at survey results with care.
The Harris Poll has put out a remarkable release that illustrates the point:
A new book, Wingnuts: How the Lunatic Fringe Is Hijacking America by John Avlon describes the large numbers of Americans who hold extreme views of President Obama. This Harris Poll seeks to measure how many people are involved. It finds that 40% of adults believe he is a socialist. More than 30% think he wants to take away Americans' right to own guns and that he is a Muslim. More than 25% believe he wants to turn over the sovereignty of the United States to a world government, has done many things that are unconstitutional, that he resents America's heritage, and that he does what Wall Street tells him to do.
ABC polling expert Gary Langer writes:

The poll starts by telling respondents “here are some things people have said about President Obama,” then asking if they think each is true or false. Fifteen statements follow, with all (excluding “he is a Muslim”) unrelentingly negative. “True” answers run from a high of 40 percent, for “he is a socialist,” to a low of 13 percent, for “he wants the terrorists to win.”

The problems are fundamental. “Some people have said” is a biasing introductory phrase; it imbues the subsequent statements with an air of credibility – particularly when you don’t note that others say something else. (That approach can have problems of its own; the “some people” vs. “other people” format implies equivalence.)

The subsequent statements, for their part, are classically unbalanced – there’s no alternative proposition to consider. A wealth of academic literature, neatly summarized here, demonstrates that questions constructed in this fashion – true/false, agree/disagree – carry a heavy dose of what’s known as acquiescence bias. They overstate agreement with whatever’s been posited, often by a very substantial margin. (This reflects avoidance of cognitive burden, which tends to happen disproportionately with less-educated respondents, as is reflected in Harris’ results.)