How do TV channels figure out how many people watched a particular episode (e.g. XX million watched American Idol)?
August 27, 2011 5:43 PM   Subscribe

How do TV channels figure out how many people watched a particular episode (e.g. XX million watched American Idol)? I often hear things like XX million viewers watched American Idol or some other show. How do the news guys / broadcasters come up with these numbers?? Surely they are not able to track what is being watched in peoples homes. So I guess this is some kind of math or projection. Any idea how this is done?
posted by r2d2 to Media & Arts (16 answers total)
Actually, they do monitor what certain households watch. They're called Nielsen Ratings. They extrapolate numbers from there, so, for every one Nielsen household that watches a show they extrapolate it to mean 1,000 other households watched it, or some number.
posted by InsanePenguin at 5:47 PM on August 27, 2011

The usual (perhaps only?) method is Nielsen ratings. The Nielsen company has picked a "representative sample" of American households who agree to hook their TV up to a box that reports back what was watched and when. (And possibly by whom - I'm not sure, but the system is pretty well-documented on wikipedia.) From that, they scale the numbers up from their small sample to the whole country.
posted by spaceman_spiff at 5:49 PM on August 27, 2011

It's surveys like the ones Nielsen conducts. I also got a Nielsen survey and a 5 dollar bill, about a year ago, I hung on to it too long and when I sent it back I never got another survey.
posted by Science! at 6:16 PM on August 27, 2011

Nielsen is the answer, but I do not think it is beyond reasonable to assume that cable companies DO KNOW what you watch.
posted by JohnnyGunn at 6:30 PM on August 27, 2011 [1 favorite]

Nielsen used to use diaries only; then they started using meters. There are probably rival services too.

My roommates and I were a Nielsen family. We put MTV on constantly to counteract what we perceived to be shameful underreporting elsewhere. It probably worked about as well as hoisting a car and putting it in reverse to run the odometer down.
posted by Clyde Mnestra at 6:42 PM on August 27, 2011 [1 favorite]

Nielsen and Arbitron are ratings companies. They send surveys or boxes to a particular demographic and record that information. There is a formula of how many people are just like those particular households and that is how they get the ratings. Now, with people calling or texting to vote on stuff like Dancing with the Stars and American Idol, there are even more accurate counts of how many households are watching a particular show at a particular time.
posted by Yellow at 6:42 PM on August 27, 2011

As Clyde Mnestra says, there is reason to believe that some of the people Nielson monitors are deliberately trying to hack the system. Everyone knows this happens, but if they abandon Nielson, there isn't anything else they can use.

So both broadcasters and advertisers agree to ignore the fact that the Nielson ratings are probably not accurate, and agree that advertising rates will be based on what Nielson says.
posted by Chocolate Pickle at 7:56 PM on August 27, 2011

I do not think it is beyond reasonable to assume that cable companies DO KNOW what you watch.

Actually, they don't. They may be able to tell what channel the cable box is tuned to, but they can't tell if the TV is on. (And if the TV is on, they can't tell if anyone is watching it.)
posted by Chocolate Pickle at 7:58 PM on August 27, 2011

This is something that happened in radio. They moved from a diary-based system, where people wrote down what they listened to, to an electronic system.

Turns out, people write down what they think they should, not what they really do. So they would write that they listened to [popular radio station] all day, when in reality, they turn it off at 10am. Same thing with TV. They will flip around, but they were "watching" [Popular Television Program].

The new devices, Portable People Meters, figure out, via magic, what people are listening to. When they rolled out, the ratings were VASTLY different than the diaries. And that was with the exact same people. So much so that they had to change the demographics because certain groups got purportedly under-represented.

So anyway, if you have digital cable, they can find out what you are watching. But I'm not sure whether they use statistical models or raw data.

Another thing to note is that the sample sizes are very small, and broadcasters occasionally play games (like how TBS used to program on the :05 and the :35 or how NBC does their super sized episodes) because it only takes a couple of people to modify their behavior to affect the ratings. The samples are statistically solid, but it is somewhat non-intuitive that a thousand people can manage to represent the whole country.
posted by gjc at 8:07 PM on August 27, 2011

Good point, Chocolate Pickle. I seem to remember reading that the Neilson boxes had people sensors in them to correct for that, but I doubt cable boxes do.
posted by gjc at 8:08 PM on August 27, 2011

I was part of a Nilson study for a while. They gave me a free cellphone with a ton of free minutes and texting on the condition that I kept it fully charged. It turned on every x-minutes or so and took a sound sample and sent it back home. Didn't actually own a tv that year, but they said that was fine, they wanted to know what ads I was exposed to on radio and at other people's homes and the like.
posted by Garm at 8:09 PM on August 27, 2011

Response by poster: So, I guess globally there probably is a company such as Nielsen in every country (or most countries) that does this sort of analysis.

Any idea which company does this in Britan?
posted by r2d2 at 8:31 PM on August 27, 2011

We got five extremely crisp Nielsen dollars this week.

Any idea which company does this in Britan?

Barb. There's a Wikipedia entry listing a load of them around the world.
posted by holgate at 9:48 PM on August 27, 2011

It is worth underlining systems such as Nielsen are ultimately there to act as arbitration devices between advertisers and channel owners. The former group would like to be able to find a way of reaching as much of their target demographic as possible whilst purchasing the least expensive combination of slots (although they will probably finesse their campaign a little more than this). The channel owners would like to sell their premium advertising slots for as much as possible and make sure the rest also generate a good income. A neutral company which divides its survey audience into demographic chunks, and then releases information showing what proportion of each chunk they think watched a given show, serves both parties by creating a common currency. Providing the demographic breakdown is not too stupid and the viewing totals are not too egregiously incorrect everybody is happy because it becomes possible to sensibly start negotiating prices.

The advertiser agrees, in advance, to pay the channel an amount for a slot based on the number of people in their target demographic group that Neilsen says were watching.

The fact that the ratings agencies can also add up the figures for all their demographics and publish a viewing total is a neat side effect for TV companies - but not what the agency is primarily paid to do.
posted by rongorongo at 4:57 AM on August 28, 2011

And if the TV is on, they can't tell if anyone is watching it.)

And if someone is watching it, they can't tell who. Which is really the biggest problem with any kind of automated ratings gathering service. For most programs, they literally do not care if you are watching if you are outside of the 18-49 age range. Younger, and you don't buy stuff, and older, you know what stuff you like to buy.
posted by smackfu at 11:11 AM on August 29, 2011

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