Audience analysis system with a viewing device operation detector

摘要

A service provider (4) and delivery network (5) to deliver multiple selectable channels to a multiplicity of households. In each household (1) is a channel selector device (2) operable by members of the household's audience to select among the channels delivered by the channel presentation device (3). The channel selector device provides data about which channel is viewed and for how long to an audience monitoring facility (7) via the household's return channel (6). The audience monitoring facility includes a data processor to subject this data to a procedure in which the viewing times for each channel are capped to a maximum permitted length if they exceed it. The data processor employs this capped data to select an array of probabilities of individuals' exposure to the presentation of particular channels for individuals of different demographies so that the data provided by the channel selector device can be resolved into data estimating the likelihood of individuals of different demographies participating in the audience. Also provided is a detector to detect if a presentation device in the household is on and operative a reference information generator to generate indications of differences between measurements of lengths of time for which channels are selected as provided by the channel selector device and measurements of time for which the presentation device is on and operative to present the channels as provided by the detector. In this way, periods of time for in channels are selected by the channel selector but the presentation device is off can be determined and the capped maximum permitted viewing length determined based on this.