The MRC has renewed accreditation for the Nielsen’s original 10 LPM markets while the remaining 15 have been accredited for the first time.

Nielsen said that the accreditation process had been “long and complex” after the MRC identified “several areas” where it could work with the ratings firm to ensure that the Active/Passive (A/P) meters used to measure digital television accurately captured all viewing.

The firm made several improvements to the A/P meters, including – among others – checking every meter in sample homes to make sure they were picking up the optimum level of codes, conducting regular analysis of how signals perform as they are re-transmitted over cable systems and introducing regular reports on the quality of codes produced by stations in each market.

Sabrina Crow, Nielsen’s SVP and managing director of local client television services, said: “These steps have allowed us to achieve greater transparency with the television industry, which has led to more confidence among clients that Nielsen is doing everything possible to ensure that television ratings are comprehensive and accurate.”