Abstract: According to the present invention there is provided a method of analysis of the audience for channels selectable by a channel selector device for presentation on a presentation device, the channel selector device providing data indicating which channels are selected and the lengths of time for which selected channels remain selected. The data relating to the lengths of time for which channels remain selected is subject to a capping procedure, whereby the indicated length of time for which a channel remains selected is reduced to a capped maximum permitted length of time if the indicated length of time exceeds the maximum permitted length, to provide capped data.