Nielsen Television Audience Measurement have been providing the ratings measurement service in Ireland since 1996. In October 2008, after a tender process, TAM Ireland awarded Nielsen Television Audience Measurement a further contract to supply television audience measurement for the Irish market from 1st September 2010 to 31st August 2017 inclusive.
Nielsen Television Audience Measurement gather information about Irish television viewing patterns from a representative panel of 1,050 homes. This equates to roughly 2,500 panel members each day. A large household survey called the Establishment Survey is conducted 3 times a year to establish the size and nature of the television population in Ireland. CSO (Age / Region / Sex) and AIMRO (Social Class) data are then used to weight the responses.
Panel controls and universes are derived from the weighted data and are updated 3 times a year. The panel is designed to be representative of the television population as defined by the Establishment Survey. Households that take part in the Establishment Survey who meet the demographic requirements of the viewing panel are invited to participate.
A device called a Peoplemeter is installed on every television set in the home. This monitors the viewing of everyone in the household. The peoplemeter is a small box that sits on top of the television. Every person in the home is assigned a button on a special remote control, which they use to login and logout of their viewing. The Peoplemeter is connected to the telephone line in the household. In the early hours of the morning, the central computer in Nielsen TAM dials each of the panel member households and collects the viewing data. The data goes through a series of rigorous quality control procedures. Reports are then produced on the ratings for the previous night's programmes. Once the data has been checked, it is transferred via modem to advertising agencies and broadcasters.
A TVR or rating as it is commonly called, represents 1% of a target audience watching a programme or ad break at a particular time. A person must be viewing for at least 15 seconds to be considered in the calculation of the rating.
Example: An average Adult rating of 15.0 for a specific programme indicates that, on average, 15% of all Adults watched the programme.
A share of viewing represents a percentage of viewers to a station or programme at a particular time, out of all people watching TV at that time.
Example: An Adult share of 30% for a programme indicates that of all adults who were watching TV at that time, 30% of them watched the programme.
TVR and Share are two of the most common figures we examine when looking at programme performance. The easiest way to decipher them is to remember that:
TVR is a percentage of all available audience, whether they are watching Television or not
Share of viewing is a percentage only of the audience who are watching TV at the time