The Interactive Advertising Bureau (IAB) late last week asked two companies that provide Internet audience measurements to submit to a third-party audit.

The IAB, a trade association representing online advertisers, sent letters to ComScore and Nielsen/NetRatings (NNR) on Friday as part of an effort to "revise out-of-date methodologies," according to IAB President and CEO Randall Rothenberg. In the letter, Rothenberg asked that ComScore and Nielsen work with the Media Rating Council, which was established by Congress in the 1960s to set standards for and oversee firms that rated television audiences.

The association is seeking the audit after finding that discrepancies exist between audience measurements of ComScore and NNR and the server logs maintained by IAB's members, the letter says. In addition, discrepancies exist between ComScore and NNT, IAB said.

"The hope is we can bring all the parties together and at least start a conversation," said Sheryl Draizen, senior vice president and general manager at IAB. "The reason why we took such an aggressive position at this point is we have not been getting real commitment from either of the companies in terms of timing or a commitment of actually getting auditing."

Neither ComScore nor NNR responded to a request for comment on the IAB request.

Draizen said the association has long urged that two firms to be more forthcoming in how they measure the online audience. The request for an audit comes as advertisers start to move more quickly to do more advertising online, Draizen added.

"[ComScore and NNR] have a material impact on people's business, so the transparency issue is so important," she said. "Every other medium has transparency, and there should be no reason we shouldn't get the same."

However, she noted that advertisers are looking for several online measurements, including unique visits, time spent on a page and page views, which makes it difficult to come up with a widely accepted standard. The problem is further complicated with the introduction of Asynchronous JavaScript and XML (AJAX) and other rich Internet technologies. Instead of making a round trip to the server every time a Web page needs to change information, it only receives the data that needs to be changed, thus eliminating a page refresh, she said

"The notion of page views is becoming obsolete because the page doesn't reload," Draizen said. "It is incumbent on the industry ... to come up with an alternative for page views."

Bob Liodice, president & CEO of the Association of National Advertisers, said he supports "any initiative that moves us closer to the real answers marketers need."