Hex: Dynamics and Probabilistic Text Entry

Abstract

Abstract. We present a gestural interface for entering text on a mobile device via continuous movements, with control based on feedback from a probabilistic language model. Text is represented by continuous trajectories over a hexagonal tessellation, and entry becomes a manual control task. The language model is used to infer user intentions and provide predictions about future actions, and the local dynamics adapt to reduce effort in entering probable text. This leads to an interface with a stable layout, aiding user learning, but which appropriately supports the user via the probability model. Experimental results demonstrate that the application of this technique reduces variance in gesture trajectories, and is competitive in terms of throughput for mobile devices. This paper provides a practical example of a user interface making uncertainty explicit to the user, and probabilistic feedback from hypothesised goals has general application in many gestural interfaces, and is well-suited to support multimodal interaction.

Tilt-Based Automatic Zooming and Scaling in Mobile Devices – A State-Space Implementation

“…Using this approach, actions require less effort, the more likely the system's interpretations of user intentions, equivalent to a fewer bits from the user, in communication terms. This was used by Barrett et al in [2], and we used this approach for text entry in Williamson & Murray-Smith [27], and the approach can be linked to methods which adapt the control-to-display ratio, such as Blanch et al [5] in classical windows interfaces. These approaches, which work with relative input mechanisms, cannot be used if we use static mappings, such as a stylus touching an explicit point on the screen.…”

A Note on Brain Actuated Spelling with the Berlin Brain-Computer Interface

“…The more fluid interaction in the BBCI system was made possible by introducing an approach which combined probabilistic data and dynamic systems theory based on our earlier work ( [16]) on mobile interfaces.…”

“…The idea for Hex-o-Spell was taken from the Hex system ( [16,17], see Fig. 1 (b)), which was designed for use on mobile devices augmented with accelerometers, where tilt control was used to maneuver through a hexagonal tesselation.…”

Variability in Wrist-Tilt Accelerometer Based Gesture Interfaces

“…Williamson and Murray-Smith [9] have developed the Hex system for inputting text on a PDA with accelerometer. This system allows the user to select letters by tilting the PDA to navigate a cursor through a series of tiled hexagons.…”