How does Nielsen Media Research know who is watching?
The way that Nielsen Media Research finds out about who is watching is to measure what a sample of television viewers are watching. For our national ratings estimates, we use a sample of more than 5,000 households, containing over 13,000 people who have agreed to participate. Since there are over 99 million households with TVs in the U.S., it might seem that a sample of 5,000 is just not big enough to represent the nation. Actually, a representative sample doesn’t have to be very large to represent the population it is drawn from. For example, you don’t need to eat an entire pot of vegetable soup to know what kind of soup it is. A cup of soup is more than adequate to represent what is in the pot. If, however, you don’t stir the soup to make sure that all of the various ingredients have a good chance of ending up in the cup, you might just pour a cup of vegetable broth. Stirring the soup is a way to make sure that the sample you draw represents all the different parts of what is in the
