Telmar.com Telmar.com eTelmar.net Home Page The Advertising Media Internet Center

Telmar Home Page Telmar.com

 

Media Guru

Guru Search Results: 14 matches were found

Wednesday, February 09, 2005 #6787
What is the formula for combining two R&Fs?

The Media Guru Answers(Wednesday, February 09, 2005 ):
Click here to see past Guru responses about "random probability"


Tuesday, December 16, 2003 #6315
How do you calculate combined frequency. If I have a cable plan in a market with a frequency of 2.6 and a broadcast tv plan with a frequency of 6.6 - what is the combined frequency?

The Media Guru Answers(Saturday, December 20, 2003 ):
The Guru will assume you are referring to average frequency, typically considered for a four week period. One actually calculates the combined Reach and GRPs and then figures the "combined" frequency. Consider the following table. If you had run 400 GRP in broadcast and had 61 reach there would be 6.6 average frequency. If you also had 100 GRP of cable and a reach of 38, there would be an average frequency of 2.6.

GRPs are simply additive for a total of 500. Reaches must be combined by a system that recognizes duplication; "random probability" will overstate a bit when you are working with two related elements such as different kinds of TV. Probability might have estimated a combined reach of 76 here but let's suppose your algorithm estimates 72.

In any case, the combined average frequency is calculated thus: divide the combined GRP (500) by the combined Reach (72) which equals 6.9; see below:

Element
Reach
Freq.
GRP
Broadcast
61
6.6
400
Cable
38
2.6
100
Total
72
6.9
500


Thursday, May 15, 2003 #5974
I can use random probability to calculate reach. Is there any way I can create a complete frquency distribution? For instance, Is it correct to add up probabilities for an individual for 4 publications (Say 0.75, 0.75, 0.5 and 0.25) and say that frequency for the person is 2.25?

The Media Guru Answers(Sunday, May 18, 2003 ):
The Guru follows neither your math nor your logic here.

If your example means the the indivisual has a 75% chance of reading the first publication, etc how would that give the person a 2.25 frequency for the 4? You are working with almost unrelated data, not to mention the overstatement of random probability in calculating reach of related media. Further, frequency distribution deals with the numbers of persons who experienced each integral frequency, i.e. how many had one exposure, how many had two exposures. No individual may have a fractional exosure.


Tuesday, April 22, 2003 #5943
i believe there is a rule of thumb when calculating the reach of trade publications. something like the first major pub in the buy gets over like 75 or 80% and then there is a average increase per added pub. It's just a rule of thumb, but it sure would be useful since we cannot define the size of the overall industry's target universe. IF you do not know this rule of thumb, how would you suggest we calculate the reach and frequency of 5 trade pubs bought with differing levels of insertions over a year. Thanks for any help!

The Media Guru Answers(Saturday, April 26, 2003 ):
Crudely: Calculate each book's circulation's percentage of the sum of the goups' circs and make this each one's individual reach. Start with the largest and calculate the added reach contribution of the others by random probability.


Friday, February 07, 2003 #5815
We've been asked to estimate reach/frequency/etc. for a plan that includes USA Today, newspapers in 8-10 major markets, spot radio in 5 markets, metro traffic in 8-10 markets, and national magazines. I think this is impossible, but can you think of any way I can provide the client with a decent estimate? I was thinking I could start by pulling delivery for USAT, magazines, New York Times, and then somehow estimating the rest.

The Media Guru Answers(Saturday, February 08, 2003 ):
The Guru sees no problem, and so does not quit understand your question perhaps. Assuming you know what reach and frequency is, you can readily determine the reach of each one of the media you mention. Most simply, you can combine them by random probability . Most reach and frequency systems on the market, like our own eTelmar, can do this for you. The only "trick" is accounting for the different geographies, but that's just artithmetic, and easy if you look at all the percentage reaches as their equivalent in thousands.


Monday, February 04, 2002 #5050
Is Telmar's multi-basing system the same thing as Fusion? And, if I'm currently doing the random probability formula to get total reach percent, what is the difference between that and Telmars calculations? Thanks.

The Media Guru Answers(Wednesday, February 06, 2002 ):
According to Telmar:
Multibasing preserves the integrity of a survey. It does not ascribe answers, and as such, avoids what we call "regression to the mean", washing away everything to averages. It preserves the leverage of a media element against any target group, not just those that leverage on demographics.

Telmar's R&F formulas use the actual turnover and duplication between media that are inherent in the survey. When there is real data, we use it.


Friday, June 29, 2001 #4538
Hello again, I have two questions about calculating reach and frequency that I have been unable to find in the archives of past responses. Perhaps you can help? 1. I normally use the formula (a+b)-(.a*b) to determine combined reach of two mediums, such as radio and print. How do I calculate the combined reach of more than two? The plan I am working on includes spot TV, spot radio and local newspaper. 2. Is it possible to determine a combined reach for more than one market or should each market be reported separately? In the past, I have provided separate delivery for each market in the same plan with a total number of gross impressions for the whole plan. Is this correct? Thanks in advance!

The Media Guru Answers(Friday, June 29, 2001 ):
1. This common formula is based on an assumption that different media duplicate their audiences according to random probability. Therefore if you follow this assumption, media may be added to combinations of media in a "chain" of the same formula. So, once you have combined TV and Radio, you can use this combination as your "a" and then combine it with newspaper as "b."

2. You can combine reaches across markets by doing a weighted average. Multiply the reach in each market by the percent of U.S. in each market. Add all the products and divide by the sum of the % U.S.


Wednesday, June 06, 2001 #4458
I'm working on a plan that includes cable and network television. I have been asked to present a rational for different schedules on three levels of spending. If i know the programs rating point, the average CPP and the cost per spot, how can I use this information to put together the total reach/frequency of sample schedules. I'm trying to get general information at this point without contacting reps to run several schedules. I need to know how to do the math by hand without a program if it's possible. Thanks

The Media Guru Answers(Wednesday, June 06, 2001 ):
It's no longer really reasonable to do the math by hand. The Guru has described calculating reach by "random probability" in the past. But the unique duplication patterns within tv schedules need to be accounted for either with tables reflecting many schedules' reaches or computer models.

Our own eTelmar offers low cost, single use, online reach calcuation.

You might try the R&F generator at U. Texas .


Wednesday, December 13, 2000 #4041
My question is regarding print measurement. For a consumer print campaign (magazines, regional) I've been asked to provide a pithy statement (to be read by a board of directors with limited marketing savvy) adressing the effectiveness of the proposed print campaign. Our account planner asked for reach and frequency, which I don't believe I can provide. I can provide circulation and readership (which would equate to reach, I believe, but that doesn't account for duplication). I am to complete the sentence "This plan results in..." Am I missing something? Thanks!

The Media Guru Answers(Sunday, December 17, 2000 ):
You have not made clear why you believe you cannot provide reach and frequency. Once you have the readership of individual publications you can begin to combine their audiences in a rough way, by "random probability." This method will understate duplication somewhat, because related publications and particularly multiple issues of the same publication duplicate more than merely randomly. Using duplication between simialr national magazines, as documented by services like MRI, you can reasonable estimate the duplication in your own schedule and thereby estimate your reach and frequency.


Tuesday, April 25, 2000 #3420
We are putting together a sponsorship package that incorporates TV spots, our company newsletter, our website and our fleet vehicles -- is it possible to estimate a combined reach/frequency for all four mediums combined?

The Media Guru Answers(Tuesday, April 25, 2000 ):
The TV is easy, using standard methods, of which you are probably aware.

The other estimates must start from simple counts of the newsletter circulation, web traffic and - the toughie - persons exposed to your fleet. Most simply, after getting a standard TV reach, convert the other media impressions to ratings and combine by "random probability."


Thursday, March 16, 2000 #3326
Dear Guru: I would like to know if there is any equation to calculate media mix reach?

The Media Guru Answers(Thursday, March 16, 2000 ):
There are several, equivalent ways to express the arithmetic to combines media according to random probability, which has been found generally adequate for the purpose of multimedia combination.

Here's an easy one:

  1. Work with two reaches at a time
  2. Treat the reach of each medium as a decimal (50 reach is 0.5)
  3. Add reach of medium A and medium B
  4. Multiply reach of medium A by Reach of medium B
  5. Subtract the product of the multiplication from the sum of the addition

Example:

  • Reach of medium A = 40, reach of medium B = 55
  • 0.4 + 0.55 = 0.95
  • 0.40 x 0.55 = 0.22
  • 0.95 - 0.22 = 0.73
  • Combined reach is 73

To add additional media, treat the combination as medium A and the next medium as B.

In some cases, a planner may have access to research which shows that an adjustment should be made for actual, measured, duplication between different media, rather than use the "random probability" formula above. In that case, more sophisticated reach calculating software packages, such as those from Telmar allow you to make the calculation and build in known adjustments.


Tuesday, September 14, 1999 #2792
What can you tell me about reach-based planning? Thank you in advance.

The Media Guru Answers(Tuesday, September 14, 1999 ):
> The usual assumption is that print and broadcast duplicate with random probability, there is no special, greater or lesser likelihood that persons in the audience of the print schedule will also be or not be in the audience of the broadcast schedule.

Mechanically. the combination may be calculated in a few equivalent ways. The Guru finds it easiest to consider the reaches as decimals (50% reach = 0.50).

Subtract the reach of print from 1 and multiply this by 1minus the reach of broadcast. Suppose print has a 40% reach and broadcast has 55%.

By subtracting 0.4 from 1 (1 - 0.4 = 0.6), you have the probabilty of the target not being exposed to print. Subtract 0.55 from 1 to get the probability of not being exposed to broadcast (1 - 0.55 = 0.45)

Multiply these two together (0.6 * 0.45 = 0.27) and you have determined there is a 27% probability of people not being exposed to either of the combined media, or a 73% reach.

This formula is typically used in media software to combine different media.

Certainly there are cases where there is a somewhat better than random probabilty of media duplication, such as TV Guide combining with a TV schedule, but that's the exception, calling for judgement.


Wednesday, September 01, 1999 #2759
Is the random probability formula used to combine reach for different media also valid when looking at effective reach (i.e. 4+ level)?

The Media Guru Answers(Thursday, September 02, 1999 ):
If you mean, can you combine the 4+ reach of one medium with the 4+ reach of another medium to get the 4+ reach of the two combined media, the answer is no.

Among those who were reached 2 or 3 times by each medium, some will now be reached 4 or more times and some will not, yet these people are not considered by combining only the two four+ groups. There are also those reached only once by the first medium and three times by the other, etc. A new, overall calculation of the frequency distribution must be done, to determine the 4+ of the combination.


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

    73% reach.

Telmar's "Media Mix" program uses these assumptions.



Back