Methodology Questions
11. What if I get a “bad” panel (such as panelists
whose listening patterns are clearly not
characteristic of my listeners)?
The size of ArbitronÂ’s PPM panel is set to provide a level of
statistical consistency equal to or greater than what we get
in the Diary service. The panel is also set up to mirror the
market on a number of different characteristics, to be sure
all groups are represented. Also, keep in mind that ongoing
“panel churn” ensures that a number of households
transition in and out of the panel every month. ArbitronÂ’s
Twin Panel study conducted in Houston-Galveston
substantiated that sampling consistency exists using the
PPM panel methodology.
12. What percentage of the panel is in-tab (or
counted in the panel) at any given time?
Our daily in-tab goal averages 75% of the installed panel.
13. Do men and women carry the meter for the
same amount of time each day?
Arbitron has not seen any evidence of differences by
gender in the Houston-Galveston or the Philadelphia
studies. Men and women have similar in-tab rates, and
both wear the meter for an average of 14.5 hours per day.
14. How will women wear the meter? (Men, at least,
can wear it on their belts.)
Based upon our exit interviews, weÂ’ve found that the
majority of women, like the majority of men, prefer to wear
the meter clipped to their clothing—usually on their
waistbands or carried in their pockets. However, women
are more likely to have used the carry accessories that
Arbitron provides (such as a lanyard) at least once.
15. Does the meter stop capturing any listening
after the green light goes off?
As long as the battery is charged, the meter is always
“listening” for codes. As long as a person meets the criteria
indicating that he or she complied for the day, then all of
the exposure detected by the meter is counted.
16. How long can a panelist stay in the panel?
A panelist can stay in the panel for up to two years.
17. WhatÂ’s the average monthly turnover of
panelists?
We are experiencing approximately eight percent turnover
of panelists per month. Panelists leave for a variety of
reasons: They can move; they may not comply and,
therefore, Arbitron asks them to leave; they choose to no
longer participate; or they are routinely rotated out of the
panel after 24 months of participation.
18. Do you have control over panel demographics?
There are several ways in which we exercise control over
panel demographics in order to have a representative
sample. We stratify our sample by geography (including
High-Density Black and Hispanic areas) to ensure a
representative starting sample. In Philadelphia, these
stratifications are geography, race/ethnicity and the
presence of 18- to 24-year-olds. We monitor each personÂ’s
compliance on a daily basis, and noncompliance triggers
phone contact from an Arbitron panel relations specialist
and other coaching.
19. If a panelist works third (overnight) shift, will
the PPM record his or her listening?
Of course; however, if the meter isnÂ’t docked at the time of
scheduled download (which normally occurs during the
overnight hours), the system will make another attempt to
download the data once the meter is back in the dock.
Also, when the meter is docked, it downloads and stores
the data so that they are ready to be sent back to Arbitron
during the next phone call. The meter does not actually
have to be docked at the time of that phone call.
20. What constitutes motion?
The motion detector is sensitive enough that normal
breathing will register as motion with the PPM.
21. What’s the “six out of seven” rule?
In order for a panelistÂ’s media exposure to be included in
the weekly audience estimates, he or she must be included
as “in-tab” for at least six out of the seven days of the
survey week. In order to be in-tab for a day, the age 18+
panelist must have carried the meter for at least eight hours
(the minimum requirement for kids age 6-17 is five hours).
So, it is possible for a panelist to contribute media
exposure for a day but not be included in the weekly
estimate.
22. If a panelist listens only five out of seven days,
will he or she be in the weekly data?
Crediting rules will report listeners in weekly estimates if
they listen six out of seven days in a week. However, daily
listening will still be credited for each of the days of the
week that the station was listened to (see question 21 for
additional details about this rule).
23. How do you reward your panelists for carrying
the meter?
Panelists may earn points by simply doing what we ask
them to do: undock the meter when they wake up, wear
their meter all day and dock the meter at night. The more
they comply, the more points they are rewarded. There are
also incentives for panelists to remain in the panel for
longer time periods.
24. How much do panelists get paid to carry the
PPM?
The amount of our incentives is considered proprietary
information; however, itÂ’s a much higher figure compared to
the diary. Keep in mind that money is not the primary
incentive in getting the panelist to cooperate; panelists
cooperate because they feel they have a “voice” in the way
radio stations are programmed.
25. What if a panelist goes on vacation?
Currently, a panel relations specialist will coach the panelist
to leave the PPM in the dock. Arbitron is also testing travel
chargers, which are similar to portable cell phone chargers,
that will allow panelists to take their PPM devices with
them.
26. Does Arbitron tell people to “wear” the PPM?
Yes. When a person agrees to be in the panel we explain
to him or her that he or she must wear or carry the PPM in
order to keep it in motion. Our printed user guides as well
as ArbitronÂ’s panel relations specialists coach panelists on
the three things they need to do to be in the panel:
• Undock the meter when they wake up.
• Keep it with them during the entire day.
• Dock it when they go to bed.
The phrase “rise to retire” is frequently used.
27. What happens if someone wears the PPM under
a heavy coat or in a purse?
The PPM is intended to mimic the human ear. It will pick up
listening as long as it can “hear” the station. Wearing the
PPM under a coat or on a purse also lowers the
background noise, so the meter can still detect the code.
28. How many seconds does it take the PPM to
register listening?
It takes the PPM about 15 seconds to register listening.