1. A method for modeling user activity with regard to a plurality of different software applications on a computing device, the method comprising, with the computing device: receiving gaze-tracking data comprising one or more real-time sensor inputs indicative of a user's gaze in relation to a display of the computing device; identifying a user interface element displayed at a location on the display corresponding to the gaze-tracking data; obtaining a semantic description of the user interface element, the semantic description comprising information about the user interface element; associating the semantic description with the gaze-tracking data; and using the association of the semantic description with the gaze-tracking data to model user activity at the computing device.