Keith Deming and Edward Lank
The inferred mode protocol is designed to determine a user’s intention in stylus interfaces with the goal of eliminating the mode problem. To accomplish this task, the system reasons using characteristics of a user’s action and features extracted from image material to determine whether a user’s gesture constitutes selection or inking. However, in many situations, uni-modal pen interfaces do not provide sufficient information to determine, unambiguously, a user’s intention. In this work, we describe our on-going research in the use of additional modalities to eliminate ambiguities that exist in the inferred mode protocol. We describe systems that incorporate stylus orientation and stylus pressure into the determination of user intention. We outline the results of a series of pilot studies analyzing the usability of these techniques. As well, we describe prototype applications developed as a result of these user trials.