Patent ID: 7483975

Claim:
A method for gathering data concerning usage of media data provided from a predetermined receiver to a user, comprising: gathering first data concerning usage of the media data by the predetermined receiver by means of a stationary monitoring system, wherein gathering the first data comprises receiving a first ancillary code encoded in the media data; gathering second data concerning usage of the media data provided from the predetermined receiver by means of a portable monitor carried on the person of the user, wherein gathering the second data comprises receiving a second ancillary code encoded in the media data; gathering first time data corresponding to at least one of (1) a time of reception of the media data in the predetermined receiver and (2) a time of recording of the media data in the predetermined receiver; gathering second time data corresponding to a time of reproduction of the media data in the predetermined receiver; comparing the first time data with the second time data to determine that one of (1) the time of reception and (2) the time of recording, occurred prior to the time of reproduction; and producing audience measurement data concerning usage of the media data provided from the predetermined receiver from the first data and the second data.