• by Joe Mandese  @mp_joemandese, December 2, 2010

An internal task force investigating how Nielsen Co. missed reporting data for Web sites with "very long" domain names has come up with a solution, and it looks to be longer than Nielsen originally indicated when the probe began. Nielsen Wednesday began informing clients that it now plans to "model" all of its online usage data for eight months leading up to October, the month for which the glitch was first identified.

Nielsen also said it would "reprocess" all of its data for the month of October, which Nielsen previously disclosed undercounted online usage for the top 1,000 Web sites an average of 5%.

Based on the new "restatement" plan, data for February through September 2010 will be modeled and restated for "statistically significant changes" and republished for clients by the end of the first quarter of 2011.

The plan calls for November and December data to be processed with November data published in January 2011, and December data published in February 2011. Nielsen did not say exactly when the reprocessed October 2010 data would be published.

"We believe that full reprocessing for October data and modeling for the data from the period prior is the optimal restatement approach given the historical data available and time required to process," Nielsen said in a letter sent to clients on Wednesday. "The restatement will allow for trend and year-over-year reporting, thus providing continuity for all clients of Nielsen NetView."