Data culled from cable and satellite
set-top boxes has been used for years by various research
firms and operators to report on and analyze TV
viewing — but Nielsen has remained cautious about using
those metrics as part of its ratings calculation.
Now, Nielsen has evidence
that set-top data can
markedly improve the accuracy
of its local-TV ratings.
Earlier this month,
the New York-based information
company shared results
from a test last summer in
three markets in which it
used set-top box data from
to refi ne ratings at the local
A key finding: By interpolating
Nielsen was able to eliminate
between 50% and 90%
of the variability for ratings
in a diary market. It used a
“weighting and factoring”
methodology to create a
hybrid rating that combined
National People Meter
data with local set-top
“One of the criticisms of existing ratings in diary markets
is that they’re too variable,” Nielsen senior vice president
of local audience measurement Pat Dineen said.
He added, “We find that usage of television increases
when we look at set-top-box-based ratings versus diary
The Nielsen test analyzed data collected in July 2010
in three Charter markets: St. Louis, where Nielsen offers
its Local People Meter service; Greenville, S.C., where it
uses set meters; and Reno, Nev., where it collects ratings
data via paper diaries.
Nielsen’s efforts to improve the accuracy of local ratings
come as competitors like TiVo and Rentrak have
launched new research products — based on set-top data
— aimed at local markets.
What’s next for Nielsen? Dineen said that “this is
the beginning of a journey for us to figure out the role
of set-top box data” in the broader context of the ratings
Whatever role set-top box data plays going forward, it
will be used to supplement Nielsen’s core panel-based
ratings, not replace them, Dineen noted. Currently, settop
box data is available
commercially for fewer
than one in five U.S.
households, he said.
set-top box data, Nielsen
should be able to provide
ratings for programs
that previously would
not have had sample sizes
big enough to produce
a statistically meaningful
number, Dineen said.
“This is the initial lab
work that allows us to
have really good conversations
with our customers,”
Dineen said. “We
want to make ratings
changes that will be good
for our clients.
As for using set-top
data on a national basis,
Dineen said the sample
size in the 20,000-household
National People Meter
is “sufficient for most viewing.” He added: “Don’t get
me wrong, most national advertisers would crave more
data. But that’s not on the short list” to incorporate settop
box data into the National People Meter ratings.
Details of Nielsen’s proof-of-concept:
Project: To determine whether set-top
data could improve accuracy of local TV
ratings in three markets
Set-top data used: Charter subscriber
data from July 2010 for St. Louis
(46,000 households), Greenville, S.C.
(12,000) and Reno, Nev. (6,000)
Next steps: Nielsen plans to consult
with clients about whether and how to
incorporate set-top data into ratings