How does the Nielson rating system work?
The Nielsen rating system is used to track viewership data of television programs in the US. [1] The system began with a focus on measuring the viewership of syndicated shows, but has expanded to include online and mobile viewership as well as digital player and app usage data. [1] A client can opt in to send Nielsen audio files for a specific program, and the files are then put in an audio repository. When the audio from a show streaming on a subscription-based on demand service matches a file in the repository, the panel measures this data. [1] The rating of a program is a fraction of the HUT (or PUT when measuring demos), which is calculated as RTG = HUT x SHARE, where HUT is the percentage of households using television, and SHARE is the percentage of TV sets in use which are tuned to a particular show. [3]
Nielsen ratings are the audience measurement systems operated by Nielsen Media Research that seek to determine the audience size and composition of television programming in the United States using a rating system [3]. However, these ratings are not the actual number of people watching a show, but rather a statistical estimate [4]. Nielsen uses a technique called statistical sampling to rate the shows [4]. Nielsen creates a "sample audience" and then counts how many in that audience view each program [4]. Nielsen then extrapolates from the sample and estimates the number of viewers in the entire population watching the show [4].