25. A system for identifying program material received by an audience member's television receiver for determining audience ratings comprising: means for detecting a first predetermined event in the functional operations of the audience member's television receiver; means responsive to the detected first predetermined event for detecting at least one second predetermined event in the programmed material; means for extracting at least one predetermined characteristic of the program material from a single frame of a video signal after the occurrence of a predetermined number of said first and second events; and means for recording the predetermined characteristic and the time of occurrence of the predetermined characteristic.
25. A system for identifying program material received by an audience member's television receiver for determining audience ratings comprising: means for detecting a first predetermined event in the functional operations of the audience member's television receiver; means responsive to the detected first predetermined event for detecting at least one second predetermined event in the programmed material; means for extracting at least one predetermined characteristic of the program material from a single frame of a video signal after the occurrence of a predetermined number of said first and second events; and means for recording the predetermined characteristic and the time of occurrence of the predetermined characteristic. 26. The system recited in claim 25 wherein said system further includes a central unit, means for transmitting the recorded predetermined characteristics and times to the central unit, wherein the central unit includes means for comparing the recorded predetermined characteristics and their times of occurrence with reference predetermined characteristics that occurred at substantially the same times to identify the program.