International Encyclopedia of Communication Online

Extract

A rating, as the term is most often used in media industries, is an estimate of the size and demographic composition of a radio, television, or Internet audience. Such metrics are of enormous importance to advertiser-supported media because they set the value of the time used to run commercial messages. The larger and more desirable the audience, the more the media can charge advertisers. Ratings are typically measures of exposure to media based on surveys of various target populations conducted by “third-party” firms independent of the sales transaction. The practice of ratings research emerged in the United States in the 1930s, and has since been refined and adopted worldwide (→ Nielsen Ratings ). However, new technologies that allow people to consume a wide range of media anywhere, at any time, coupled with the desire of advertisers to reach ever-more narrowly drawn markets, have strained current systems of audience measurement. Ratings companies have responded by developing new methods to keep pace with the demands of their client industries (→ People-Meter ). Audience ratings are most often based on some form of probability sampling, and as such are subject to the same kinds of non-response and sampling error that occur in any survey research (→ Survey ; Sampling, Random ). In dozens of countries, ratings companies provide commercial and government clients with estimates ... log in or subscribe to read full text