Patent attributes
Apparatus, methods and articles of manufacture for determining an operating mode of a recording/playing device are disclosed. An example apparatus includes an extractor to extract signatures associated with a first signal associated with a tuner that is to tune to a program signal, a second signal associated with a recording/playing device that is to at least one of record and play a program, and a third signal associated with a receiver coupled to the recording/playing device. The example apparatus also includes a recording detector to detect a recording signal generated by the recording/playing device during recording of the program to form a recorded program. Also included is a correlator to correlate the first, second, and third signals and a processor to identify the operating mode of the recording/playing device based on detection of the recording signal and correlation of two or more of the first, second, and third signals.