Arbitron to increase Cell-Phone-Only Sample yarget in all PPM markets.

Arbitron Inc. announced that it will increase the sample target for cell-phone-only households in all Portable People Meter markets to 15 percent by year end 2010. In an interim step, the current target of 7.5 percent will be raised to 12.5 percent in PPMTM markets by year-end 2009.

“Arbitron has developed, tested and is presently implementing an address-based sampling method to identify and contact cell-phone-only households,” said Bob Patchen, chief research officer, Arbitron Inc. “This new method is more efficient than the manual dialing procedures we had been using and thus allows us to substantially increase the number of CPO persons included in our panels. We are also retaining the random-digit-dialing (RDD) sampling method for landline homes because that approach enables telephone contact with a higher percentage of landline homes not listed in telephone directories. These unlisted landline households are more likely than listed ones to contain Hispanics, African-Americans and young adults. The better response achieved with telephone contact can improve the overall representation of these groups in our PPM samples.”

“Increasing the number of cell-phone-only households in our PPM samples is an important element in our ongoing programs to enhance the participation of 18-34 year olds of all races and ethnicities,” said Owen Charlebois, president, Technology and Research Development. “As the number of households that can be reached only by cell-phone continues to grow, Arbitron will update its methodologies to better include this important segment of the population.”

For the New York PPM radio ratings service, Arbitron has already announced that it would increase the cell-phone-only sample target to 15 percent by July 2010.

Cell-phone-only sampling plans for diary markets

On December 15, 2008, Arbitron announced plans to expand the introduction of cell-phone-only sampling to 151 diary markets in Spring 2009 and to all diary markets (except Puerto Rico) by Fall 2009.

In diary markets, Arbitron also plans to use an address-based sample frame as the foundation of its cell-phone-only sample, while maintaining the random-digit-dial (RDD) sample frame for landline households.

The expansion of cell phone-only sampling to 151 diary markets in the spring assumes that the company is able to complete the development of software necessary to support the rollout as scheduled. If the company is not able to develop the software as expected, the planned acceleration of cell phone-only sampling could be delayed. Arbitron expects to confirm its plans for cell-phone-only sampling for the Spring 2009 survey by late February.