Arbitron to increase sample size for radio ratings

Arbitron to increase sample size for measurement of radio audiences

• On 4:36 pm EDT, Friday October 2, 2009

COLUMBIA, Md. (AP) -- Arbitron Inc. said Friday it would increase the sample size of the listeners it tracks for its radio ratings service.

Arbitron's Portable People Meter measures radio audiences. The company said it plans to increase the sample size for those 18 to 54 years of age by 8 percent by the end of 2010. Another 2 percent increase is expected by mid-2011.

Arbitron also set a minimum sample size of 750 people age 6 and older by mid-2011 for all its Portable People Meter markets. For Memphis, Tenn., and Providence, R.I., Arbitron will increase the minimum sample size to 675 by the end of 2011.

Overall, Arbitron expects to boost its sample size by 10 percent for those over 12 years of age by mid-2011.

Columbia, Md.-based Arbitron shares were up 35 cents to $21.22 on Friday.