Arbitron details January 2009 sample quality metrics for PPM markets

Arbitron released a summary of sample quality metrics for the January 2009 Portable People Meter survey report (January 8, 2009-February 4, 2009).

On average, across 14 PPM currency markets for the January 2009 survey reports, PPM panels delivered:
• Persons age 6 and older sample targets at 107%;
• Persons age 18-54 sample targets at 101%;
• Black Persons age 6 and older sample targets at 103%; and
• Hispanic Persons age 6 and older sample targets at 112%.
On average, in the eight PPM markets that qualify for Spanish-language weighting, the PPM panels delivered:
• Hispanic Spanish-Dominant sample targets at 138%; and
• English-Dominant sample targets at 107%.

Among the Persons age 18-34 demographic, the average performance across the 14 markets is 93% of the sample target. By race/ethnicity, Black Persons age 18-34 averaged 87% of target and Hispanic Persons age 18-34 averaged 100% of target.

In-tab rate for Persons 6+ across the 14 PPM-currency markets for the January 2009 PPM survey averaged 79%, 4 percentage points above the benchmark of 75%, and an increase of 5%age points over the Holiday 2008 survey period.

Sample Performance Indicator (SPI) for the 14 PPM currency markets posted a 19.7 average, an increase of 1.3 points over the Holiday 2008 survey period average of an 18.4 SPI.

Arbitron has recently noted that it has been over-delivering the sample for total Persons 6+ in an effort to boost sample size in key demographic groups. The company has implemented new initiatives designed to help it manage the panels closer to the target for Persons 12+, while continuing to achieve average sample benchmarks for young adults and Black and Hispanic persons. Arbitron currently anticipates that the PPM sample sizes for Persons 6+ will average closer to the target (100 DDI), and that the average DDI will be near 85 for Persons 18-34 within the next few months.

In-Tab Sample Performance by Demographic 
Designated Delivery Index (DDI) 
January 2009 PPM survey month (January 8, 2009-February 4, 2009)

Designated Delivery Index or DDI is the actual sample size for a given demographic divided by the target sample size for the demographic (times 100). A DDI of 100 means that Arbitron achieved its sample target; a DDI of greater than 100 means that Arbitron exceeded its sample target. 
* “Year Two+” market; DDI benchmarks/guarantees based on a 13 survey-month rolling average

Persons 6+ Sample Performance by race/ethnicity 
Designated Delivery Index (DDI) 
January 2009 PPM survey month (January 8, 2009-February 4, 2009)

– Population in indicated market too small to be reported