Gallup, whose final 2012 election poll showed Republican challenger Mitt Romney leading President Barack Obama, said today that its likely-voters screen and too few interviews on the East and West coasts contributed to its failure to forecast the final vote accurately.
The Gallup poll commissioned a study of its methods after its last pre-election survey gave Romney a 1-point lead over Obama, who won re-election by almost 4 percentage points.
“That’s not where we wanted to be,” Frank Newport, Gallup editor-in-chief, told reporters at a briefing today in Washington.
The firm said it was reviewing its models, had already changed some of the methods it follows in conducting surveys, and would make other adjustments as needed.
In a report prepared with the University of Michigan, Gallup said the way it determined likely voters, such as screening for those who have voted in previous elections and their interest in this one, tilted its sample toward Romney.
“What we’re doing is evaluating the whole process of estimating likely voters,” Newport said.
The firm said its samples skewed more to Midwestern and Southern voters rather than those on the East and West coasts, where Obama was strongest.
It discovered that its telephone samples appeared to be tilted toward Republicans and raised questions about the way it weighted for cell phone-only respondents.
Its questioning to determine race and ethnicity of respondents also produced flawed information, Gallup said.
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