More Election Post-Mortem

Is a poll like every other poll? On Thursday the The Pew Research Center released a study showing that the much-cited "moral values" response on exit polls appears to be influenced by its presence or absence on the survey instrument. On fixed-list surveys, moral values registered a 27% response, but in open-ended prompts, only 14%. From the survey:

The survey findings parallel exit poll results showing that moral values is a top-tier issue for voters. But the relative importance of moral values depends greatly on how the question is framed. The post-election survey finds that, when moral values is pitted against issues like Iraq and terrorism, a plurality (27%) cites moral values as most important to their vote. But when a separate group of voters was asked to name ­ in their own words ­ the most important factor in their vote, significantly fewer (14%) mentioned moral values. Regardless of how the question is asked, the survey shows that moral values is the most frequently cited issue for Bush voters, but is seldom mentioned by Kerry voters.

For those of you who *hate* methods classes, this is why understanding biases in seemingly innocuous is fundamental to being a good researcher.