A method of identifying a media source, comprising: generating , by executing an instruction with a processor of a measurement apparatus, first signature information with a first time stamp value based on media presented via a media delivery device ; comparing (306; 612; 614), by executing an instruction with the processor of the measurement apparatus, the first signature information with the first time stamp value to second signature information with a second time stamp value, wherein the second signature information is derived from a library of signature information accessible by the measurement apparatus; generating (306; 616), by executing an instruction with the processor of the measurement apparatus, a collection of matching signature information based on the comparison of the first and second signature information; identifying, by executing an instruction with the processor of the measurement apparatus, a source of the media presented via the media delivery device based on a match of the first signature information and the second signature information; in response to the match of the first signature information and the second signature information, determining, by executing an instruction with the processor of the measurement apparatus, whether the first time stamp value is greater than the second time stamp value; and performing (308; 800), by executing an instruction with the processor of the measurement apparatus, a time shift analysis to determine and report that the media presented via the media presentation device was time shifted when the first signature information and the second signature information match and the first time stamp value is greater than the second time stamp value. generating , by executing an instruction with a processor of a measurement apparatus, first signature information with a first time stamp value based on media presented via a media delivery device ; comparing (306; 612; 614), by executing an instruction with the processor of the measurement apparatus, the first signature information with the first time stamp value to second signature information with a second time stamp value, wherein the second signature information is derived from a library of signature information accessible by the measurement apparatus; generating (306; 616), by executing an instruction with the processor of the measurement apparatus, a collection of matching signature information based on the comparison of the first and second signature information; identifying, by executing an instruction with the processor of the measurement apparatus, a source of the media presented via the media delivery device based on a match of the first signature information and the second signature information; in response to the match of the first signature information and the second signature information, determining, by executing an instruction with the processor of the measurement apparatus, whether the first time stamp value is greater than the second time stamp value; and performing (308; 800), by executing an instruction with the processor of the measurement apparatus, a time shift analysis to determine and report that the media presented via the media presentation device was time shifted when the first signature information and the second signature information match and the first time stamp value is greater than the second time stamp value. <EOS>