Television ratings provide useful information for advertising companies, TV producers, and parents. The companies that offer such a service are publicly or privately sponsored and the information is used to buy and sell TV time as well as make program decisions.

A forerunner for television ratings was a study, sponsored by the cable TV industry, on the effects of violence on children. The result heightened the need for program guidelines and limitations which were subsequently self imposed by the program produces. The study revealed that "psychologically harmful" violence was prevalent on broadcast and cable television programs and that the risks to viewers involved learning to behave violently, becoming more desensitized to the harmful consequences of violence and becoming more fearful of being attacked.

The study recommended that producers and others in the television business limit the amount of violence and increase the number of viewer advisories. It also suggested that parents watch television with their children and critically evaluate the programs with them.

A well known television rating company on whom the industry and public rely is the Nielsen Media Research. It provides television information services in the United States and Canada serving national and local customers. The company began in 1923 and was one of the first research companies to measure the audience for the radio broadcasting and advertising industry. In 1950 it expanded to include television. The data is collected by means of an electronic measurement system called the Nielsen People Meter. These meters are placed in a sample of 5000 households in the United States, randomly selected by the Nielsen Media Company. The meter measures what programs or channel is being tuned and who is watching. The information is stored in the metering system and automatically retrieved by NMR computers.

The TV Parental Guidelines is another rating system that is designed to help parents decide which shows are appropriate for their children. The ratings are broken into two parts; age based or audience rating and content-based ratings. The ratings are usually displayed in the TV guide and at the start of a show in the upper left hand corner of the TV screen. The rating system is voluntary and the network or producer of each show is the one that decides on a program's rating.

There many other rating companies in existence who are attempting to call attention to the importance of television guidelines. The bottom line however lies with the viewer as to what type of program is desired for viewing