  This paper explores the estimation of user attention in the setting of a
cooperative handheld robot: a robot designed to behave as a handheld tool but
that has levels of task knowledge. We use a tool-mounted gaze tracking system,
which, after modelling via a pilot study, we use as a proxy for estimating the
attention of the user. This information is then used for cooperation with users
in a task of selecting and engaging with objects on a dynamic screen. Via a
video game setup, we test various degrees of robot autonomy from fully
autonomous, where the robot knows what it has to do and acts, to no autonomy
where the user is in full control of the task. Our results measure performance
and subjective metrics and show how the attention model benefits the
interaction and preference of users.
