Methods, apparatus, systems and articles of manufacture to determine source information for media content output by a media rendering device operable to output media content from a plurality of different sources are disclosed. An example method disclosed herein comprises detecting media content output by the a media rendering device, the media content having a media variable associated therewith, detecting a plurality of user commands, detecting a change in the media variable associated with the media content output by the media rendering device, selecting, based on a time limit, a user command from the plurality of detected user commands to use with the detected media variable change to determine source information, and providing the detected media variable change and the selected user command to a processor to determine a source of the media content output by the media rendering device.