Despite all the sophisticated thinking that goes into a media plan, we tend to take mechanical details of the ratings for granted. We know a little about samples (bigger is better), we know a meter is the best measurement tool and we know a diary is the worst. And we also know “There will always be diaries in Duluth.”
But most planners don’t know what goes on behind the scenes. A tour of Nielsen’s new Global Technology Center reveals a modern information factory staffed with dedicated workers who are trained to stay within the lines. Those lines are the editing rules that give intensely specific answers to the dozens of “what if” questions that come up as the sloppy real world encounters the discipline needed to ensure that each media exposure is treated exactly the same way.
Editing rules are getting close attention these days as Nielsen prepares to switch the top 10 markets from the diary to the Local People Meter as the basis for demographic television ratings. The diary rules have been in place for decades. They provide a standardized way of handling the many variations in the way diary keepers report their viewing.
Editing the Diary
Editing rules first determine whether or not a diary is intab-that is, whether it should even be counted in the ratings. A diary can be rejected if it is not filled in, if its entries are duplicates of another diary, if it is illegible or incomplete (“I forgot to record some viewing”) or if it has any of a host of other defects.
The rest of the diary-editing rules determine which station will be credited with reported viewing. As they watch TV, the diary keepers are asked to write down a station’s call letters, channel number and program title. Assigning credit is easy when all three match. When they don’t, there is an editing rule for just about every situation. The most important consideration is program title.
For instance, one editing rule says: “In diary entry situations where there is a call letter (or affiliation) and channel num ber match, but the program title given is aired on a different station, credit will go to the station that carries the program at that particular time.”
Complex situations are researched by Nielsen’s diary editors with the aid of a computer-assisted diary-checking system that holds four weeks of quarter-hour-by-quarter-hour program schedules for more than 1,500 TV stations. Despite the many rules and mechanical aids, the process often requires the editor’s subjective interpretation of what the diary keeper intended.
Computerized Rules
Mechanical systems such as the People Meter replace an editor’s subjective judgment with computerized rules that temporarily disqualify any household that, for one reason or another, fails to provide usable data. First comes the household edit. A home can fail if it tunes to a new broadcast station or cable network that has not yet been registered with Nielsen for that home. Homes fail if there is a gap in the data caused by problems with the phone line or Nielsen’s equipment. And a home can fail if it changes its cable supplier or gets a new TV set that has not yet been metered.
These faults are usually remedied within a day or so, but homes adding a digital video recorder such as TiVo are currently taken out of the sample as being “technically difficult.”
Nationally, about 90 percent of installed homes pass the household edit in an average day. Their viewing is counted in the HUT, household rating, share and household audience projections.
Homes passing the household edit must next pass an extensive set of rules that check the persons data. For instance, a home is taken out of persons tab if the set is on and there have been channel changes but no buttons have been pushed for more than 30 minutes, and if this represents more than 10 percent of a household’s viewing.
Also, a home fails if the People Meter has been unplugged for more than five minutes in a measured day. On average, about 85 percent of national People Meter homes pass the persons viewing edits in an average day. Their viewing is reflected in the PUT, persons ratings, share and projected thousands.
Scrutiny Coming
Editing and reporting rules are especially important as new technologies come online. By mid-2005, DVR/PVR households will be included in the set meter and People Meter samples.
We can expect close scrutiny of the rules governing how Nielsen counts recorded viewing that occurs up to seven days after the initial telecast. Clearly, this esoteric side of audience measurement will have a direct effect on the ratings we use to plan television campaigns.
Roger Baron is senior VP and media research director for FCB.