In a bid to stave off allegations about manipulation of its ratings, A.C. Nielsen conducted a validation exercise today. According to TAM chief L.V. Krishnan, the validation exercise done across two points and consisting of two samples (one containing part of the list doing the rounds in media offices and one without that part) in April 2001 and 1 September 2001 highlights the fact that there has been no manipulation of ratings.

According to Krishnan, the Mumbai list which has been leaked has only 228 homes. "Our current panel strength is 312 homes and only 35 per cent of the leaked list homes exist; the rest have been done away with," he points out.

"We constituted two samples. One - set A - which has identities revealed and another which we called Total which had set A and the sample which did not have the identities not revealed," he reveals. "If the ratings were truly manipulated, then the ratings for the two sets of samples below would vary dramatically."

"But both in terms of channel share and Top shows in both April 2001 and September 2001 for both the samples, there were very marginal differences," he says. "This shows that there was no rigging." (Click here for Tam's presentation on the validation exercise)

"We reassure the industry that there has never been any tampering of the data," he points out. "Steps are being taken to enhance security systems. On the technology front, we are examining new options for retrieving data through telephone/radio/cellular modems - minimising manual interfaces."

Now it is over to industry to say its piece.