How do tv channels know how many people watch any one program?

certain people selected by I don't know, have special boxes which record what they are watching. Only a certain number of people have these, then the results are multiplied by the population who own television sets, or pay their licence fees and a number such as 4.5 million is generated, so it is not exact. At least that is the way it used to be done, I think it still is, but with the advent of digital tv, there may be a way to monitor what people are watching via the set top boxes, this will only work properly when the nation is completely digital, and if they can record it this way, they could get a far more accurate reading. As far as I know, the method I described above is the one still used.

Good question! I think they use a sample audience and draw there conclusions from there. (Nobody has ever asked me). Im not sure tho - so go easy on the thumbs down .. lol

They use a system called the Nielsen rating system. If I understand correctly they gather information 2 ways, through extensive surveys, and they place a certain number of readers in special boxes in peoples homes (voluneteers) and they track what people watch. They use those figures to extrapolate to the general population.

Audience figures are produced by the Broadcasters Audience Research Board Ltd. ( Been done like this for many years ) Have a look at www.barb.co.uk for all the info.

If they do it the same way in the UK as they do in the USA a Ratings Taking company puts a electric device on a person's tv set that tracks what they watch- also they may have them fill out a 'diary' of what they watched/ what channel and for how long--this people are usually picked at randam or fit into some core group ( age/income) That Ratings company then have some kind of math forumla ratio- many other simular example one household doing the ratings device/diary will =1,000 other households

The Nielsen ratings company and other atings company mail out little schedule books for viewers to fill out and return telling them what they watched and for how long. these ratings are then extrapolated and are the basis of how many viewers are watching a show at any given time. Participants are often paid a nominal fee for filling out the books.

I think the Neilson Ratings

They recruit volunteers who record every programme they watch. The number of watchers are classed as a representitive proportion, and from data held by the TV companies they get an average numbers of viewers to a certain programme.

There's a company called "Nielson" which puts monitor boxes on a select "sampling" of televisions throughout the nation. From that sampling - they estimate a nationwide / local average.