1 matches were found
- Friday, April 30, 1999 #2481
Is there any way to calculate duplication across a media plan using several media (e.g. print and radio and TV), or can I only get a duplication analysis within a media (radio duplicaton and then another duplication factor for print, etc , etc)
I use telmar for research with simmons and arbitron access and we also use JDS for buys.
- The Media Guru Answers(Friday, April 30, 1999 ):
The standard assumption in media planning is that duplication between different media is purely at random. Therefore, the random probability formula IS USED:
- Express the reach of each medium as a decimal (50% reach = 0.5)
- Multiply the reach of one medium by another to determine the duplication.
- Subtract the duplication from the sum of the two reaches to get the net reach
So, if you have a 40% reach in TV and a 55% reach in Print, multiply
0.4 x 0.55 to get 0.22
subtract 0.22 from 0.4+.55 and get 0.73 or
73% reach of the combined media.
There are a variety of ways to do the calculation. The Guru actually prefers to use the probablilty of not seeing each medium (reach as a decimal subtracted from 1.0) When these are multiplied they give the net probability of not seeing any of the media. When this result is subtracted from 1, the final result is net reach. This style is particulary useful for combining several media at once.The example would combine this way:
- 1-0.4 = 0.6
- 1-0.55 = 0.45
- 0.6 x 0.45 = 0.27
- 1-0.27 = 0.73 or
Telmar's "Media Mix" program uses these assumptions.