Here we go:
Nielsen, a global information and measurement company, reports data about the TV programs people watch and, in some cases, what they listen to and buy. Nielsen data helps generate ratings, which are used to indicate whether a program is successful and which influence whether a program will be renewed for another season.
Nielsen ratings are based on a random sampling of people in households — known as "Nielsen families" — who are a representative share of all TV viewers. In 2015 it's believed there are 116.3 million TV homes, with nearly 296 million people age 2 and older in these homes [source: Nielsen].
The shows Dave records on his DVR — as long as he watches them within three days of their original airtime — is of particular importance to Nielsen's live+3 ratings. Live+3 ratings refer to shows that are watched within the first three days after the time they originally air.
Live+3 ratings take into account DVR viewing, something that's of increased interest to rating followers in a binge-watching world. Unfortunately, it may not go far enough. For example, if you're catching up on your DVR recordings of the entire previous season of "The Americans," it won't count toward the Nielsen live+3 ratings because the shows originally aired weeks ago.
Other Nielsen ratings, such as live+7, may provide a more accurate picture of delayed viewing, but only if the shows are watched within seven days of the original airing. In addition, Nielsen tracks live+SD to identify shows that are recorded and watched the same day [source: Barker].
Nielsen was founded by market analyst Arthur Nielsen and has been measuring TV viewing habits since the 1950s [source: Nielsen]. There are critics of the system, however, who believe binge-watching an entire season of a comedy show on Hulu or streaming it on-demand through a cable service should count toward Nielsen ratings. There are ways Nielsen captures the data. Watching shows through an online or streaming service does count toward its "online viewers" rating. This rating, however, carries little weight. For example, a Netflix show with 15 million weekly viewers and 1.5 million live views will rate only slightly better than a show with 1.5 million live viewers alone [source: Herman].
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