In-Place-Ink: Toward More Direct Handwriting Interfaces.

An indirect handwriting interface using a separate window is a de facto standard interface in most of major pen computing systems. In this paper, we study the potential of the other less explored handwriting interfaces, which we call In-Place-Ink (IPI) interfaces, where a user writes directly on a target text input area. We first conducted a preliminary experiment to determine the optimal input area dimensions for direct handwriting input, and based on the results designed two IPI interfaces: a discrete IPI (DIPI) interface and a continuous IPI (CIPI) interface. We then conducted a main experiment using form-filling tasks to evaluate their efficiencies and collect user feedback about them in comparison with a conventional indirect writing (IW) interface. The experiment results showed that CIPI required significantly lower completion time for a form-filling task than other interfaces, and was comparable to the IW interface in terms of user preference. We hope our report of designing and evaluating the two IPI interfaces may stimulate future research efforts toward more direct handwriting interfaces.