Process

• Nielsen gathers ratings data by selecting 25,000 homes consisting of what the company determines to be typical television viewers. The homes are equipped with box-like devices that are attached to the television sets. The box tracks everything that household members watch or record. Nielsen collects the data and uses it to determine the ratings and shares. A rating of 1.5, for instance, means Nielsen estimates that 1.5 percent of all households in the U.S. that have televisions were tuned in to a particular program. A share of 3.5 means that 3.5 percent of all households that were actually watching television at a given time were tuned in to the program.
  
  

DVR Significance

• As the Nielsen ratings take into account recorded shows as well as those viewed when they originally aired, DVRs have an impact on ratings figures. However, according to the New York Times website, unlike ratings taking during the original broadcast time, figures that include DVR viewership are not available immediately. The results of what are known as "time-shifted viewing" are not released by Nielsen until at least two weeks later.
  
  

Impact

• A sample of figures from September, 2010 illustrates that DVR use increases Nielsen ratings. An episode of the show "Glee" earned a 5.6 rating on the date it aired, which included those who viewed it as it aired or watched a playback that same day. When taking into account DVR viewership over a period of three days after the original airing, the rating jumped to 6.3. "Two and a Half Men" and "Law & Order SVU" each experienced an increase in the range of 15 percent to 20 percent.
  
  

Considerations

• DVRs may have less of an impact for certain types of shows. A new show that generates little interest may not receive a significant ratings boost from DVR use. The ratings for the first airing of "Lone Star" in September 2010 saw the rating only increase from 1.3 to 1.5 after time-shifted viewing results were tabulated. Shows that are originally aired live also tend to be recorded less, as evidenced by "Dancing with the Stars," which only showed an increase from 5.1 to 5.3.