Ratings scandal in Providence?

[Chuck Igo]

----- Original Message ----- 
From: "Brian Vita" <brian_vita@cssinc.com>
To: "'Chuck Igo'" <chuckigo@maine.rr.com>; "'Kevin Vahey'" 
<kvahey@comcast.net>; <bri@bostonradio.org>
Sent: Thursday, August 07, 2008 4:00 PM
Subject: RE: Ratings scandal in Providence?

>> What is the total number of diaries that are sent to a given market that 
>> six make up a statistical significance?  I would think that they'd have 
>> enough out in the market that 6 would end up in the margin of error.<<

it takes surprisingly few in-tab diaries to make or break a station's 
fortunes in regards to final ratings.  it's all proportional - number of 
diaries sent out in relationship to the Metro population.  of the diaries 
returned, they struggle to work with and count as many as possible.  simple 
things such as handwriting, incorrect or unknown call leters, station 
nicknames, frequencies, etc lead to a good portion of the returns to be not 
counted, or those portions not counted.

i can't speak for Providence, but i know that for the greater Portland 
ratings, with a population of several hundred thousand considered in the 
"metro," an average in-tab used diary count is plus/minus 550.  6 diaries 
with a significant time-spent-listening to any one station can create a 
tremendous impact on the final numbers

--Chuck Igo