Two weeks ago, I used quotes from the classic movie Casablanca for the ongoing Cumulus – Nielsen litigation. This week, let’s channel an even older movie, The Wizard of Oz (1939). The line “Pay no attention to that man behind the curtain” is apt when describing how PPM credits listening. Nielsen doesn’t advertise the rules that operate “behind the curtain,” nor do they hide them, and any electronic system will have a whole series of intricacies.
Consider all the editing twists in the diary service, and that’s just a paper system. Almost no one outside of the company knows exactly what the Nielsen wizards do (some of you may prefer to use wicked witches instead of wizards), so let’s cover their activities here. If you’re reading this on Monday morning when my column first appears in Barrett Media, have some strong coffee handy.
Our trip down the yellow brick road begins with two rules that you may have heard of and that I’ve written about in the past: the lead-in edit and the bridging edit. If you are thinking, “Huh?” here are the reasonable explanations. The lead-in edit assumes that the meter needs a bit of time to pick up codes, so if the panelist didn’t just switch from one station to another, one minute is credited ahead of the time that the meter picks up a solid code.
If your brain is functioning right now, the answer is yes – a less than three-minute quarter hour is possible when you think about actual listening.
The bridging edit does just that. It bridges. If a panelist listened to station A, then the data shows a gap of up to one full minute, followed by a resumption of listening to station A, that “blank” minute is credited to station A, which makes sense. So far, so good.
Next is the PPM code itself. A PPM code contains a small amount of information, including a signal that tells the meter that information is on the way, a unique code that identifies the station, and a time stamp from the encoder. The codes are transmitted if the station is broadcasting some level of energy, as the code is a sound and must operate “underneath” the station’s audio. If a PPM-encoded radio station or stream runs dead air, it’s as good as off-the-air for Nielsen purposes, as the code can’t be sent.
When a panelist’s meter receives codes, it does a couple of things. First, it must store the code. It also must add its own time stamp, as well as look at the quality of the code. Generally, all the codes stored by a meter for a given day will be sent to Nielsen via the cell network.
Now let’s look at what happens after a panelist’s codes arrive at Nielsen and are processed. The system starts with 15-second increments and rolls them up to 30-second increments based on “clock minutes,” in other words, 7:00:00 to 7:00:30 and 7:00:30 to 7:01:00. The system allows only one station to get credit for a 30-second increment. What if someone changes stations within a 30-second increment? The rule is usually the “last best code.” The exception: if the last code is not “complete” – because sometimes complete codes don’t come through to the meter – then the last complete code (representing a station) will get the credit.
What if the code is “incomplete,” but there are no other saved codes in that 30 seconds? The system looks 15 minutes behind and ahead for that panelist to see if there is a complete code that is off by one character. If it finds one, credit is given to that station. That clears up most of the incomplete codes.
What of the remaining incomplete codes? The PPM system looks five minutes before and after that code was received and will credit it to a complete code in the same medium. Radio goes to radio and TV to TV. Got it so far? Don’t worry – only my Western Kentucky University students must take exams.
The next step is to go from 30-second increments to minutes, and much like three minutes gets you the quarter hour, 30 seconds earns you the minute. If KAAA “wins” the first 30 seconds and KBBB wins the second 30 seconds, both get credit for that minute. Now the wizard – I mean system – builds a quarter hour, and under the current rules, three minutes earns you credit for the quarter hour from that panelist, who is hopefully in your core demo.
As you’ve probably figured out, multiple stations can get credit for the same quarter hour. One other note: all along, the system has worked with PPM codes. Once the system determines which code or codes will get credit for the quarter hour, the codes are matched to the database, and now the credit is given to KAAA, KBBB, and maybe even KCCC!
In the past, it was possible for three stations to receive credit for the same quarter hour. With 3MQ, my assumption (although I’ve not verified this with anyone at Nielsen) is that five or more stations could get credit for the same quarter hour. It’s not likely, but it’s possible.
That’s how PPM crediting works, and other than the change to 3MQ, it’s worked that way since Arbitron implemented the system 20 years ago. This isn’t meant for radio wizards to think about ways to game the system, but for educational purposes. Once you understand it, you’ll realize you’re not in Kansas anymore – or even Columbia, Maryland!
Let’s meet again next week.
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