Confidence of attentiveness of a consumer of a media object on a media playback device is estimated by monitoring for a user action performed on a mobile computing device while the media objects are being played back; responsive to a user action, retrieving descriptors for the media object; computing a relevance of the detected user action and the descriptors using correlation; if sufficiently correlated, determining a degree of confidence that the user is attentive to the media object; and recording the one user action, the media object descriptors, and the degree of confidence into digital results for reporting and usage by other devices and processes to improve viewership, readership, and listenership measurements.