Nielsen ratings

"Sweeps" redirects here. For the Transformer, see Sweeps (Transformers).

Nielsen ratings are audience measurement systems developed by Nielsen Media Research, in an effort to determine the audience size and composition of television programming in the United States. Nielsen Media Research was founded by Arthur Nielsen, who was a market analyst whose career had begun in the 1920s with brand advertising analysis and expanded into radio market analysis during the 1930s, culminating in Nielsen ratings of radio programming, which was meant to provide statistics as to the markets of radio shows. In 1950, Nielsen moved to television, developing a ratings system using the methods he and his company had developed for radio. That method has since become the primary source of audience measurement information in the television industry around the world.

Measuring ratings

Nielsen Television Ratings are gathered in one of two ways:

1. Viewer "diaries", in which a target audience self-records its viewing or listening habits. By targeting various demographics, the assembled statistical models provide a rendering of the audiences of any given show, network, and programming hour.
2. A more technologically sophisticated system uses Set Meters, which are small devices connected to televisions in selected homes. These devices gather the viewing habits of the home and transmit the information nightly to Nielsen through a "Home Unit" connected to a phone line. The technology-based home unit system is meant to allow market researchers to study television viewing habits on a minute to minute basis, seeing the exact moment viewers change channels or turn off their TV. In addition to set meters, individual viewer reporting devices, such as people meters, have allowed the company to separate household viewing information into various demographic groups, but so far Nielsen has refused to change its distribution of data of ethnic groups into subgroups, which could give more targeted information to networks and advertisers.

Changing systems of viewing have impacted Nielsen's methods of market research. In 2005, Nielsen began measuring the usage of digital video recordings such as TiVo. Initial results indicate that time-shifted viewing will have a significant impact on television ratings. The networks are not yet figuring these new results into their ad rates at the resistance of advertisers.

Ratings/share and total viewers

The most commonly cited Nielsen results are reported in two measurements: ratings points and share, usually reported as: "ratings points/share". As of September 1, 2009, there are an estimated 114.9 million television households in the United States. A single national ratings point represents one percent of the total number, or 1,149,000 households for the 2009–10 season.

Share is the percentage of television sets in use tuned to the program. For example, Nielsen may report a show as receiving a 9.2/15 during its broadcast, meaning that on average 9.2 percent of all television-equipped households were tuned in to that program at any given moment, while 15 percent of households watching TV were tuned into the program during this time slot. (Nielsen re-estimates the number of TV-equipped households each August for the upcoming television season.) The difference between rating and share is that a rating reflects the percentage of the total population of televisions tuned to a particular program while share reflects the percentage of televisions actually in use.

Because ratings are based on samples, it is possible for shows to get 0.0 share, despite having an audience; the CNBC talk show McEnroe was one notable example. Another example is The CW Television Network show, CW Now, which received two 0.0 ratings in the same season.

Demographics

Nielsen Media Research also provides statistics on specific demographics as advertising rates are influenced by such factors as age, gender, race, economic class, and area. Younger viewers are considered more attractive for many products, whereas in some cases older and wealthier audiences are desired, or female audiences are desired over males.

In general, the number of viewers within the 18-49 age range is more important than the total number of viewers. According to Advertising Age, during the 2007-08 season, Grey's Anatomy was able to charge $419,000 per commercial, compared to only $248,000 for a commercial during CSI, despite CSI having almost five million more viewers on average. Due to its strength in young demos, Friends was able to charge almost three times as much for a commercial as Murder, She Wrote, even though the two series had similar total viewer numbers during the seasons they were on the air together.

Commercial ratings

Nielsen also provides viewership data calculated as the average viewership for only the commercial time within the program. This "Commercial Ratings" first became available on May 31, 2007. Additionally, Nielsen provides different "streams" of this data in order to take into consideration delayed viewing (DVR) data, at any interval up to seven days. C3 was the metric launched in 2007. C3 refers to the ratings for average commercial minutes in live programming plus three days of digital video recorder playback.

Sweeps

Electronic metering technology is the heart of the Nielsen ratings process. Two types of meters are used: set meters capture what channel is being tuned, while People Meters go a step further and gather information about who is watching in addition to the channel tuned.

Diaries are also used to collect viewing information from sample homes in many television markets in the United States, and smaller markets are measured by paper diaries only. Each year Nielsen processes approximately 2 million paper diaries from households across the country for the months of November, February, May and July — also known as the "sweeps" rating periods. Seven-day diaries (or eight-day diaries in homes with DVRs) are mailed to homes to keep a tally of what is watched on each television set and by whom. Over the course of a sweeps period, diaries are mailed to a new panel of homes each week. At the end of the month, all of the viewing data from the individual weeks is aggregated.

This local viewing information provides a basis for program scheduling and advertising decisions for local television stations, cable systems, and advertisers.

In some of the mid-size markets, diaries provide viewer information for up to three additional “sweeps” months (October, January and March).

Nielsen 2008-2009 sweeps dates

November 2008	30 October – 26 November, 2008
March 2009	March 5 – April 1, 2009
May 2009	April 23 – May 20, 2009
July 2009	July 2 – July 29, 2009

Nielsen 2009-2010 sweeps dates

November 2009	October 29 – November 25, 2009
February 2010	February 4 – March 3, 2010
May 2010	April 29 – May 26, 2010
July 2010	July 1 – July 28, 2010

Note: The February 2009 sweeps period was moved to March so that the ratings would not be affected by any problems created by the February 17th switchover of the USA's analog broadcast television signals to digital. When, in early February, the digital transition date was moved to June 12, the "February" sweeps period for 2009 remained in March.

Criticism of ratings systems

There is some public critique regarding accuracy and potential bias within Nielsen's rating system. In June 2006, however, Nielsen announced a plan to revamp its entire methodology to include all types of media viewing in its sample.

Since viewers are aware of being part of the Nielsen sample, it can lead to response bias in recording and viewing habits. Audience counts gathered by the self-reporting diary methodology are sometimes higher than those gathered by the electronic meters which provide less opportunity for response bias. This trend seems to be more common for news programming and popular prime time programming. Also, daytime viewing and late night viewing tend to be under-reported by the diary.

Another criticism of the measuring system itself is that it fails the most important criteria of a sample: it is not random in the statistical sense of the word. Only a small fraction of the population is selected and only those that actually accept are used as the sample size. There are only 25,000 total American households that participate in the Nielsen daily metered system. The resident population of the United States as of 2009 is about 307 million people. As a result, the total number of Nielsen homes only amounts to 0.0000814332248% of the total American population, meaning that 99.9999186% of Americans have no input at all into what is actually being watched. Compounding matters is the fact that of the sample data that is collected, advertisers will not pay for time shifted (recorded for replay at a different time) programs rendering the 'raw' numbers useless. In many local areas, the difference between a rating that keeps a show on the air and one that will cancel it is so small as to be statistically insignificant, and yet the show that just happens to get the higher rating will survive. As the possible choices increase so does the margin of error resulting in the sampling sizes being too small.

In 2004, News Corporation retained the services of public relations firm Glover Park to launch a campaign aimed at delaying Nielsen's plan to replace its aging household electronic data collection methodology in larger local markets with its newer electronic People Meter system. The advocates in the public relations campaign charged that data derived from the newer People Meter system represented a bias toward underreporting minority viewing, which could lead to a de-facto discrimination in employment against minority actors and writers. Nielsen countered the campaign by revealing its sample composition counts. According to Nielsen Media Research's sample composition counts, as of November 2004, nationwide, African American Households using People Meters represented 6.7% of the Nielsen sample, compared to 6.0% in the general population. Latino Households represent 5.7% of the Nielsen sample, compared to 5.0% in the general population. By October 2006, News Corp. and Nielsen settled, with Nielsen agreeing to spend an additional $50 million to ensure that minority viewing was not being underreported by the new electronic people meter system.

Another criticism of the Nielsen ratings system is its lack of a system for measuring television audiences in environments outside the home, such as college dormitories, transport terminals, bars, and other public places where television is frequently viewed, often by large numbers of people in a common setting. In 2005, Nielsen announced plans to incorporate viewing by away-from-home college students into its sample. Internet TV viewing is another rapidly growing market for which Nielsen Ratings fail to account for viewer impact. Apple iTunes, atomfilms, YouTube, and some of the networks' own websites (e.g., ABC.com, CBS.com) provide full-length web-based programming, either subscription-based or ad-supported. Though web sites can already track popularity of a site and the referring page, they can't track viewer demographics. To both track this and expand their market research offerings, Nielsen purchased NetRatings in 2007.

Furthermore, a new problem has developed primarily with the February sweeps. For the 2001-2002 season, the National Football League moved Super Bowl XXXVI to February, when it was placed in the sweeps period, because of the September 11, 2001 terrorist attacks, which postponed the NFL schedule a week. Because of that, starting with the 2003-04 season, the NFL moved the Super Bowl into the sweeps period.

Since the move of the Super Bowl into the sweeps period, Sunday nights in the sweeps period in February is almost guaranteed to be a winner for the network holding the big event on each of the four Sundays – the Super Bowl (alternates among NBC, CBS, FOX), Grammy Awards (moved to Sundays since 2003 except during Olympics, CBS), Daytona 500 (finish moved into prime-time in 2007 until it was moved back to the daytime in 2010; FOX), or Academy Awards (moved into the sweeps period in 2004, ABC) and every fourth year, the Winter Olympic Games (next telecast 2010, NBC). The later games of the World Series have also been played in November in recent years.

Annual top-rated shows

Nielsen began compiling ratings for television nationally beginning in 1950. Before that year, television ratings were compiled by a number of other sources, including C. E. Hooper and Variety. Hooper was bought out by Nielsen in February 1950.

These are the programs that finished with the highest average Nielsen rating in each television season:

Year	Program	Network
1950–1951	Texaco Star Theater	NBC
1951–1952	Arthur Godfrey's Talent Scouts	CBS
1952–1953	I Love Lucy
1953–1954
1954–1955
1955–1956	The $64,000 Question
1956–1957	I Love Lucy
1957–1958	Gunsmoke
1958–1959
1959–1960
1960–1961
1961–1962	Wagon Train	NBC
1962–1963	The Beverly Hillbillies	CBS
1963–1964
1964–1965	Bonanza	NBC
1965–1966
1966–1967
1967–1968	The Andy Griffith Show	CBS
1968–1969	Rowan & Martin's Laugh-In	NBC
1969–1970
1970–1971	Marcus Welby, M.D.	ABC
1971–1972	All in the Family	CBS
1972–1973
1973–1974
1974–1975
1975–1976
1976–1977	Happy Days	ABC
1977–1978	Laverne & Shirley
1978–1979	Three's Company
1979–1980	60 Minutes	CBS
1980–1981	Dallas
1981–1982
1982–1983	60 Minutes
1983–1984	Dallas
1984–1985	Dynasty	ABC
1985–1986	The Cosby Show	NBC
1986–1987
1987–1988
1988–1989
1989–1990	The Cosby Show, Roseanne	NBC, ABC
1990–1991	Cheers	NBC
1991–1992	60 Minutes	CBS
1992–1993
1993–1994	Home Improvement	ABC
1994–1995	Seinfeld	NBC
1995–1996	ER
1996–1997
1997–1998	Seinfeld
1998–1999	ER
1999–2000	Who Wants To Be A Millionaire?	ABC
2000–2001	Survivor: The Australian Outback	CBS
2001–2002	Friends	NBC
2002–2003	CSI: Crime Scene Investigation	CBS
2003–2004
2004–2005	American Idol	Fox
2005–2006
2006–2007
2007–2008
2008–2009

See also

• Appreciation Index
• Broadcasters' Audience Research Board (BARB) (UK)
• Crossley ratings
• C. E. Hooper
• List of most-watched television broadcasts
• List of television stations in North America by media market
• List of US daytime soap opera ratings

Further reading

• Anthony Bianco and Ronald Grover. "How Nielsen Stood Up to Murdoch" BusinessWeek. September 20, 2004.

External links

• Nielsen Media Research website
  • Nielsen Media: FAQs - About the "Sweeps"
• Slate (magazine): How Does "Sweeps" Week Work? (February 16, 2004)
• Nielsen Global Technology and Information Center website
• Nielsen Media Research: Everyone Counts
• Information on Nielsen's Anytime Anywhere Media Measurement Initiative.