Information about the Nielsen Ratings
Many people are confused about ratings. What does it mean, exactly, when a television series has a rating of 1.4? We consulted the FAQ for Nielsen Media, as well as some local experts and hope the following information will assist in understanding the way the rating system works.
What are Ratings and Shares?
The terms rating and share are basic to the television industry. Both are percentages.
A rating is a percent of the universe that is being measured, most commonly discussed as a percent of all television households. As such, a rating is always quantifiable, assuming you know the size of the universe (TV households, persons, women 18 - 34, and so forth).
A share is the percent of households or persons using television at the time the program is airing and who are watching a particular program. Thus, a share does not immediately tie back to an actual number, because it is a percent of a constantly changing number - TV sets in use. Shares can be useful as a gauge of competitive standing.
How Does the System Work?
Nielsen Media Research continually measures television viewing with a number of different samples all across the U.S. The first step is to develop representative samples. This must be done with a scientifically drawn random selection process. No volunteers can be accepted or the statistical accuracy of the sample would be in jeopardy.
Nationally, there are 5,000 television households in which electronic meters (called People Meters) are attached to every TV set, VCR, cable converter box, satellite dish or other video equipment in the home. The meters continually record all set tuning. In addition we ask each member of the household to let us know when they are watching by pressing a pre-assigned button on the People Meter which is also present. By matching this button activity to the demographic information (age/gender) we collect at the time the meters are installed, we can match the set tuning - what is being watched - with who is watching. All these data are transmitted to Nielsen Media Research's computers where they are processed and released to our customers each day.
In addition to this national service, we have a slightly different metering system in 55 local markets. In each of those markets Nielsen Media Research gathers just the set-tuning information each day from more than 20,000 additional homes. We than process the data and release what we call "household ratings" daily. In this case we can report what channel or program is being watched, but we don't have the "who" part of the picture. To gather that local demographic information, we periodically (at least 4 times per year) ask another group of people to participate in our diary surveys. For these estimates, we contact approximately 1 million homes each year and ask them to keep track of television viewing for one week, recording their TV viewing activity in a diary. This is done for all 210 television markets in the United States in November, February, May and July and is generally referred to as the "sweeps".
The Population According to Nielsen
Nielsen Media Research creates a Universe Estimates using a variety of sources. Data from Claritas, Inc. and Public Use Files from Federal surveys, as well as the Nielsen Media Research home-by-home and person-by-person records, which has been collected since the 1940's.
According to these estimates there are 102,200,000 TV homes in the U.S. for the 2000-2001 season. There are 12,260,000 African-American TV homes and 8,940,000 Hispanic-American TV homes. This makes up 12 and 9 percent of the total household population.
Looking at the Nielsen National Sample of 5,000 TV homes, there is roughly the same breakdown. Approximately 12 percent of the sample is African-American and approximately 9 percent of the sample will be Hispanic-American.
What is a Universe?
The total population base that the sample is designed to represent.
What are Demographics?
Demographics are simply the characteristics of human beings: gender, age, religion, ethnicity, marital status, educational level, profession, and income.
What's important about Gender?
Basic demographic data, such as gender, can provide information about television viewers. For instance, males tend to watch different types of programs than females.
What's important about Age?
Basic age can provide information about television viewers because of life cycle implications. For instance, older people often have more time to view than younger people.
What's important about Household Income?
Television networks use the demographic data provided by the Nielsen Media Research to establish advertising rates. One of the factors used by Nielsen in measuring audiences is Household Income.
What's important about Ethnicity?
According to Nielsen Media Research, African-American households account for 12 percent of the total household population. Hispanic households account for 9 percent. Persons of different ethnic backgrounds may watch different types of television programs.