Only one in five Web users say they notice the "AdChoices" icon, which is aimed at telling consumers about online behavioral advertising, according to research unveiled today by the University of Pennsylvania's Joe Turow. Most Web users -- 55% -- say they don't know whether they have seen the icon, while 24% say they have not, according to Turow. Those findings come from a survey of 1,503 Americans about attitudes regarding online ad targeting. Turow's study also found that the overwhelming majority of respondents -- 86% -- disliked targeted political ads. (That data was released in July, but survey results about the AdChoices icon wasn't made public at the time.) Turow, a professor at the Annenberg School for Communication, presented his research Tuesday at a meeting convened by the Commerce Department. The AdChoices icon -- the centerpiece of the ad industry's self-regulatory efforts -- is served in around 1 trillion ad impressions each month. The icons consist of a lower-case 'i' inside a triangle and are accompanied by the phrase AdChoices; they typically appear in the top corner of behaviorally targeted ads. Consumers who click on an icon are taken to pages where they can learn more about online behavioral advertising -- or how companies mine users' Web-surfing history in order to serve them ads -- and opt out of that form of advertising. Turow says that the 20% awareness rate seems low, given the large number of impressions served. "I would hope the awareness would be substantially higher than that," he says. But the Interactive Advertising Bureau's general counsel Mike Zaneis says he believes Turow's findings show the self-regulatory program is making progress. "Twenty percent of market awareness for an icon program after a little more than one year in operation is progress that any brand marketer could envy," he says. A study released in April by researchers from Carnegie Mellon University also raised questions about whether the icons effectively inform Web users about data-based advertising. For that report, researchers examined how 1,500 Web users interpreted the icons, taglines and landing pages. Most users "mistakenly believed that ads would pop up if they clicked on disclosure icons and taglines," the report says. More than six in 10 users -- 63% -- believed that opting out would stop online tracking; most ad networks only promise to stop sending targeted ads to people who opt out, although some also stop tracking those users. But Lou Mastria, managing director of the umbrella group Digital Advertising Alliance, says it's premature to draw negative conclusions -- especially given that the group launched a new educational initiative earlier this year. That campaign directs Web users to the site www.youradchoices.com, which features three videos and an opt-out mechanism. "There's a little bit of a rush to judge the icon, even though we haven't been in the market that long," Mastria says. "It's very early days."