A news ticker on the TSA homepage promotes a recent poll that finds "Most OK with TSA full-body scanners." (Credit: TSA)

The major media polls, once again, are performing a public disservice by their claims that most Americans “support” full body x-rays at airport screening, or the alternative – an aggressive full body pat down.

These polls are cited by the Transportation Security Administration (TSA) in rebutting numerous complaints against the new screening procedure. Passengers who want to skip the all-revealing x-ray machines can submit instead to a pat down, which allegedly includes probing one’s groin and other private body parts.

Objections to this invasive process, the TSA defends, are trumped by widespread public support for the new procedures, as revealed by the media polls. As the New York Times reports, “The agency has so far responded to the complaints by calling for cooperation and patience from passengers, citing polls showing broad support for the full-body scanning machines.” (italics added)

But what exactly do these polls show?

CBS News’ Nov. 15 poll reported that 81% support the full-body x-ray machines. (Credit: CBS)

The most recent CBS News poll claims that “4 in 5 Support Full-Body Airport Scanners.” The specific question asked by the CBS interviewers was:

Some airports are now using ‘full-body’ digital x-ray machines to electronically screen passengers in security lines. Do you think these new x-ray machines should or should not be used at airports?

Should           81%
Should not    15
Unsure             4
TOTAL          100%

There are so many problems with this question and results that it’s hard to know where to begin.

The question does not allow a respondent to say what I think most respondents would say, if given a chance: They simply “don’t know” whether these machines should be used or not, because they don’t know anything about the effectiveness or safety of the machines.

The above results suggest that just 4% of Americans are unsure about the issue, implying an incredibly informed public. But the low number of “unsure” responses is a consequence of a forced-choice format, which presses respondents to come up with an opinion even if they don’t have one. Had the pollsters added a tag line to their question, “or don’t you know enough to say?”, it’s quite likely that the vast majority would have chosen that option.

After all, how could most people have an opinion on the matter, when most Americans haven’t gone through a scanner – and probably hadn’t even heard of the issue before being asked by CBS News?

But CBS chose not to ask respondents whether they had heard of the scanner prior to the poll, or whether they had personally gone through one. The reason? The forced choice format produces more appealing results from a journalistic point of view. If the vast majority of people don’t have an opinion on an issue, that’s hardly interesting to report – even when it’s the truth.

Another problem with the CBS News question wording is the lack of an alternative. Pollsters know that in the absence of an alternate solution to a problem, respondents will succumb to “response acquiescence” – a tendency to give a positive answer. The alternative to having the scanners is to continue with metal detectors as is currently done.

Had the pollsters asked respondents whether they preferred the current screening procedures or the new ones with the scanner (or didn’t they know enough to say), the results would likely have revealed a very different public opinion.

Previous polls (see Pollingreport.com for other results) use the same forced choice format, and also ask all respondents their opinion, regardless of whether they have any knowledge of the scanners or the issue. For example, last January (8-10), when the scanners were first being adopted in a limited number of airports, CNN asked this question:

As you may know, new machines called full-body scanners could be used at airports to scan passengers for weapons or explosives that cannot be detected by the machines currently in use. The new machines display an image of what the person being scanned looks like naked but that image is shown only to security personnel in a closed room at some distance from the machine itself. Do you think full-body scanners like that should or should not be used in U.S. airports?

Should          79%
Should not   20
Unsure            2
Total            101% (exceeds 100% because of rounding error) 

Like the CBS News poll, this poll used a forced-choice format and did not ask respondents whether they knew anything about the scanner. Nor did it give an alternative method of screening.

Instead, the question first informed respondents that the scanner was used “to scan passengers for weapons or explosives that cannot be detected by the machines currently in use,” and then asked whether they “should” be used or not. With such leading questions, it makes one wonder if the media pollsters aren’t really working for the TSA!

In January 2010, Gallup also polled Americans on body scanners, and reported that 78% of “travelers” approved of a “full body scan” of passengers. This poll differs in that it asks the question only of “travelers” – defined as people who had taken two or more air trips in the past year (representing about 27% of the sample). But the other problems noted for the CBS and CNN polls are present here as well.

Gallup made no effort to find out how many of the travelers had actually gone through one of the new body scans, so the answers were mostly hypothetical. In fact, Gallup’s wording reflects the fact that most people had not experienced such scanners, because it notes that “one method of airport security that is expected to be used more widely at U.S. airports is a full body scan of passengers….” (see below).

And, of course, the question was forced choice, pressuring respondents to come up with an opinion whether or not they had one. Also, it provided no alternative. Like the other two polls, this one creates the illusion of public support, based on hypothetical responses of people who mostly have had no experience with the scanners – and, of course, have little knowledge as to the method’s effectiveness.

The truth about public opinion is that most people simply don’t know enough about the scanners to have an opinion. Even people who have gone through the scanners don’t know enough about the effectiveness of the scanners to judge whether the invasive pictures and pawing of one’s body significantly contribute to security.

There are real issues of security and safety and civil rights that have to be addressed with the new procedures. The TSA’s response, of hiding behind the faux public opinion reported by our major media organizations, is unacceptable. The pollsters’ behavior, of creating the faux public opinion in the first place, is a blight on the media polling industry.

UPDATE: 11/20/2010 10:22 AM EST: StinkyJournalism has sent this story to CBS and CNN for comment and will update with any response.

UPDATE: 11/20/2010 1:27 PM EST:  Added section about Gallup’s polls.

George F. Bishop is Professor of Political Science and Director of the Graduate Certificate Program in Public Opinion & Survey Research at the University of Cincinnati. His most recent book, The Illusion of Public Opinion: Fact and Artifact in American Public Opinion Polls (Rowman & Littlefield, 2005) was included in Choice Magazine’s list of outstanding academic titles for 2005 (January 2006 issue).

David W. Moore is a Senior Fellow with the Carsey Institute at the University of New Hampshire. He is a former Vice President of the Gallup Organization and was a senior editor with the Gallup Poll for thirteen years. He is author of  The Opinion Makers: An Insider Exposes the Truth Behind the Polls (Beacon, 2008; trade paperback edition, 2009). Publishers’ Weekly refers to it as a “succinct and damning critique…Keen and witty throughout.”