Evening star., 1953-08-17

Hooper's diary studies, by Tren'
dex's phone calls, by Nielsen!
mechanical devices in sets, BY
Pulses recall interviews-the en-.
tire television audience is taker
into consideration.
| This is possible-in case you
dozed through yesterdays lecture
or cut class-because of the law
of probability. A small cross Sec
ton, if it is truly representative
will accurately mirror a very
large entirety. It will not be 10C
per cent accurate, of course. II
will be much closer to 100 pei
cent than you would believe
without seeing it demonstrated,
close enough for all practical
purposes.
X y
This is demonstrated in COL
legeS with regularity to show STU
dents that the law of probability
is a fact. You can prove it to
yourself if you want to obtain
a barrel and 100000 marbles
say 10000 white, $4,000 red, 20,-
600 blue. $4,000 green and 10000
yellow.
You place the marbles in the
barrel, mix them well so that
marbles of each color are equally
distributed throughout the bar
rel. Each marble then will have
an equal chance of being Sc
lected by someone reaching into
the barrel Now you blindfold a
friend and have him start pick
ing out marbles.
The first hundred removed are
not likely to be 10 white, Is red,
20 blue. 25 green and 80 yellow.
But the ratio of colors in your
small sample will represent the
actual ratio Of colors in the bar
rel with an error of only 4 or S
per cent. Remove another 100
marbles and this small error will
be cut considerably in your
sample of 200 out of 100000.
BY the time you have removed
400 or 500 marbles, the sample
will indicate the true distribution
OF colors in the barrel so accu-
rately that there is no point in
going further. 1t works time after
time. The odds against its work.
ing are in the nature of those
stratospheric 400-million-to-one
odds you hear about in roulette.
X X II
This proves the Soundness of
the program ratings in the class
room, or in your basement If
your really want to get 100000
marbles and give it a try. In
practice. the ratings demonstrate
their own soundness.
Different sets of people fill out
those diaries recording their tele-
viewing week after week. Differ
ent sets OF people are called by
telephone and asked what pro-
gram they are watching. Yet
there is never a drastic change,
Bishop Fulton j. Sheen's rat
ing climbed gradually as Milton
Berle's dropped. However, Berle
never dropped from third place
to twentieth while the bishop
leaped from twentieth to third in
the space of a month as a new
set OF viewers was polled. AS
the cross section grows it keeps
demonstrating itself to be a true
one, accurately indicating all
viewing habits.
X ~
The ratings are deplored in
some quarters with the charge
that their influence is out of
proportion. It probably is, but
the ratings do fill a need. A
newspaper or magazine can show
audited circulation figures to let
an advertiser know how big a po-
tential audience he will have
For television and radio, these
rating services are the best eco
nomically feasible way to doing
the same thing.
The ratings-those obtained
with diary studies, at any rate
can show the broadcasters other
things. 1t is as important for
them to know, for instance, who
is watching as what is being
watched. The ARB can tell
them that boxing's audience is
IS per cent men and 35 per cent
women, while wrestling's audi
ence is about equally divided be-
tween the sexes. Boxing, clearly,
would be less than ideal tele-
vision show for a man selling
home permanentS.
The ratings will really come
into their own when some net
work executive with authority
suddenly sees them in a brand
new light. He will note with sat-
isfaction that one of his pro-
grams has a steady audience Of
20 million viewers, then he will
have this thought.
That means that 140 million
people do not see 1t. II 100 mill
lion Of them can't that leaves 40