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)
Rank |
Market |
Persons 6+ |
Persons 18-54 |
14-market average |
107 |
101 |
|
1 |
New York (non-embedded) |
105 |
98 |
2 |
Los Angeles |
110 |
104 |
3 |
Chicago |
110 |
98 |
4 |
San Francisco (non-embedded) |
109 |
98 |
5 |
Dallas-Ft. Worth |
111 |
99 |
6 |
Houston* |
101 |
100 |
7 |
Atlanta |
105 |
97 |
8 |
Philadelphia* |
104 |
107 |
9 |
Washington, DC |
105 |
102 |
11 |
Detroit |
108 |
103 |
19 |
Nassau-Suffolk |
107 |
104 |
26 |
Riverside-San Bernardino |
113 |
106 |
35 |
San Jose |
104 |
101 |
38 |
Middlesex-Somerset-Union |
106 |
98 |
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)
Rank |
Market |
Black 6+ |
Hispanic 6+ |
14-market average |
103 |
112 |
|
1 |
New York (non-embedded) |
104 |
133 |
2 |
Los Angeles |
95 |
124 |
3 |
Chicago |
108 |
115 |
4 |
San Francisco (non-embedded) |
105 |
129 |
5 |
Dallas-Ft. Worth |
93 |
111 |
6 |
Houston |
100 |
104 |
7 |
Atlanta |
96 |
– |
8 |
Philadelphia |
122 |
– |
9 |
Washington, DC |
102 |
92 |
11 |
Detroit |
101 |
– |
19 |
Nassau-Suffolk |
104 |
79 |
26 |
Riverside-San Bernardino |
– |
115 |
35 |
San Jose |
– |
152 |
38 |
Middlesex-Somerset-Union |
104 |
80 |
– Population in indicated market too small to be reported