One of America’s leading website audience measurement services has had to restate its Q4 2002 figures after admitting a flaw in its new methodology.

ComScore Media Metrix introduced new monitoring software and an expanded panel in October, but has now revealed that (among other errors) the revised system under-represented web use at the workplace.

It has therefore recalculated results for the last three months of 2002. For some websites, the difference is considerable: Primedia saw audiences for its sites jump by 25% to 56 million; eBay was up 19% to 54m users; and Terra Lycos enjoyed a 21% boost to 51.6m.

The revision is particularly embarrassing for WeatherBug, which has been hyping itself as “the No. 1 source for weather information on the web, according to ComScore Media Metrix.” Under the new figures, it slips to number two behind

Data sourced from: New York Times; additional content by WARC staff