Friday, September 24, 2004

Public Agenda Behind the Headlines: The Poll Truth , September 17, 2004

Public Agenda Behind the Headlines: The Poll Truth, September 17, 2004:
"As we head into the season of fast-and-furious political polling, it can be difficult for the average person to keep things straight. Today, for example, three different polls were released; one by the Pew Research Center says President Bush and Sen. John Kerry are now neck-and-neck again, as does the new Harris Poll, while Gallup's latest survey says President Bush has widened his lead to 13 points. How can they all be true?"

In judging any survey, it's critical to know who's being surveyed and how. One key difference to watch for is between registered voters and "likely voters" -- the people pollsters believe are more likely to show up on Election Day. Polling organizations seeking likely voters will ask respondents a series of questions designed to figure out someone's past voting behavior and level of interest in the current election. That can change the results even in the same survey. This week's Gallup poll had registered voters at 52 percent for Bush and 44 percent for Kerry, compared to 55 percent and 42 percent among likely voters. The difference in the previous Gallup poll was even more pronounced -- registered voters were essentially tied, while Bush led among likely voters.

The trouble is that different polling organizations use different methods to identify likely voters, so even then the results can vary from poll to poll.…

In a tight, hard-fought campaign like this one, when the poll is taken can also matter. All three polls were … conducted at different times (Harris on Sept. 9-13, Gallup on Sept. 12-15, and Pew in two waves on Sept. 8-10 and Sept. 11-14.). If the campaign was a blowout for Bush or Kerry that might not matter, but in a close election a few days can make a big difference. And of course, in a tight race, survey results can be within the three- or four-point margin of error -- which essentially should be considered too close to call.
con·cept: Public Agenda Behind the Headlines: The Poll Truth , September 17, 2004