From the day that you started in radio, if you were working in a rated market, you were informed about the importance of a quarter-hour. To a normal everyday person, a quarter-hour refers to fifteen minutes of time. This column will attempt to demystify (or perhaps mystify) the term for radio people because it can be defined in a few different ways.
Let’s start with a clock. In the world of Nielsen Audio, a quarter-hour refers to a clock quarter-hour. Every hour has four “clock” quarter hours; :00-:15, :15-:30, :30-:45, and :45-:00.
To get listening credit from either a PPM panelist or a diary keeper, you need five minutes of listening to your station during one of those “clock” quarter hours. If the panelist or diary keeper listens from 7:05-7:10, you get credit and that five minutes is treated as fifteen minutes of listening.
However, if the panelist or diary keeper listens to you from 7:11-7:19, you get bupkis (a fine research term) because you didn’t have five minutes of listening in a “clock” quarter-hour, even though the person listened for eight minutes.
With me so far?
Where the five-minute credit rule came from is likely lost in the mists of time, but it’s still the rule today and we all play to that rule. However, there are differences between the PPM and diary systems. In PPM, any five minutes in the clock quarter-hour earns credit. In PPM, listening to one encoded station from 7:02 until 7:05 and again from 7:10 to 7:12 will earn one quarter-hour of listening credit (3 + 2 = 5 for those of you who were asleep in first grade!). That doesn’t fly in the diary service although when reviewing diaries, you’ll see very few diary keepers who are that anal so it’s not as big of a deal.
PPM has one more twist. When the system was designed, it was understood that it might take some number of seconds for the meter to pick up a “good” code, so a one-minute lead-in edit was added. Let’s stick with the example above and assume that someone was leaving their house in the morning to head to their post-COVID work. Also, assume that they weren’t using any PPM-encoded radio or TV prior to getting in their car.
The panelist starts the car (wearing their meter, of course!) and listens to an encoded radio station. Assume the time was 7:11. The Nielsen system will add one minute to the start of that listening episode, in other words, the lead-in edit. The station receives credit for four minutes, 7:11 to 7:15 plus the one-minute lead-in edit (going back to 7:10), meaning the station earned a quarter-hour with four minutes of listening. Oddly enough, PPM for TV uses different rules.
Have I confused you some more?
The lead-in edit does not apply when there was encoded listening ahead of that listening event. For radio, the obvious example is switching stations in the car. The meter was already receiving code so no lead-in edit is applied. In other words, you still need five minutes in the clock quarter-hour to receive credit for the full quarter-hour.
There is also something called a bridging edit. If the panelist’s meter, for whatever reason, loses the code for a station for up to one minute, but the listening was to station A on both sides of the “lost minute”, PPM will credit the minute to station A, “bridging” the two listening sessions. The assumption is that the code was temporarily lost and because it was the same station on both sides of that “lost minute”, why not give that station the credit for that minute? The logic is sound, so there’s another situation where a quarter-hour can be, well, certainly less than fifteen minutes and potentially less than five minutes.
In a diary market, you likely know the value of the vertical line which has no PPM equivalent. Nielsen even includes the line in the diary’s example page and testing has shown that in many cases, diary keepers do look at the example to better understand how to fill it out. The line or more accurately, an editor’s interpretation of what constitutes a line, can be a gem or cubic zirconia.
There are a number of twists in the diary edit rules that explain how to credit a line and the difference can be hours of listening or just a few minutes depending on how the diary keeper entered it in their diary.
That’s the short version of what constitutes a quarter-hour and just this much can make your head spin as well as causing you to question why you got into this business in the first place.
I’m a huge advocate of “the more you know, the better you’ll do” so think about this and if you have questions, send them to me.
Let’s meet again next week.
