  A well-designed control-to-display gain function can improve pointing
performance with indirect pointing devices like trackpads. However, the design
of gain functions is challenging and mostly based on trial and error. AutoGain
is a novel method to individualize a gain function for indirect pointing
devices in contexts where cursor trajectories can be tracked. It gradually
improves pointing efficiency by using a novel submovement-level
tracking+optimization technique that minimizes aiming error
(undershooting/overshooting) for each submovement. We first show that AutoGain
can produce, from scratch, gain functions with performance comparable to
commercial designs, in less than a half-hour of active use. Second, we
demonstrate AutoGain's applicability to emerging input devices (here, a Leap
Motion controller) with no reference gain functions. Third, a one-month
longitudinal study of normal computer use with AutoGain showed performance
improvements from participants' default functions.
