The Use of User Modeling in Machine Learning

If you build a good model of a user, that means it's representative and predictive. For instance, something I have been doing for more than a decade is to try to infer how people allocate attention on different screens based on how they move them out. These are things that you can measure for free basically by running larger scale studies. If you really want to pay attention to how people behave on the web, for instance, then the mouse has been shown to be a good proxy of the eye gaze.