Per Ola Kristensson

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Zhai and Kristensson (2003) presented a method of speed-writing for pen-based computing which utilizes gesturing on a stylus keyboard for familiar words and tapping for others. In SHARK<sup>2</sup>:, we eliminated the necessity to alternate between the two modes of writing, allowing any word in a large vocabulary (e.g. 10,000-20,000 words) to be(More)
We propose a method for computer-based speed writing, SHARK (shorthand aided rapid keyboarding), which augments stylus keyboarding with shorthand gesturing. SHARK defines a shorthand symbol for each word according to its movement pattern on an optimized stylus keyboard. The key principles for the SHARK design include high efficiency stemmed from layout(More)
1. intRoDuCtion Throughout human civilization, text has been an indispensable channel of communication. Modern computers equipped with desktop keyboards have dramatically increased the ease and volume of text-based communication in the form of email, text chat, and Web posting. As computing technologies expanded beyond the confines of the desktop, the need(More)
Mobile text entry methods are typically evaluated by having study participants copy phrases. However, currently there is no available phrase set that has been composed by mobile users. Instead researchers have resorted to using invented phrases that probably suffer from low external validity. Further, there is no available phrase set whose phrases have been(More)
We propose a new research direction for eye-typing which is potentially much faster: dwell-free eye-typing. Dwell-free eye-typing is in principle possible because we can exploit the high redundancy of natural languages to allow users to simply look at or near their desired letters without stopping to dwell on each letter. As a first step we created a system(More)
We present a system designed to help blind people navigate around obstacles. Our system perceives the environment in front of the user using a depth camera (a Microsoft Kinect). The system identifies nearby structures from the depth map and uses sonification to convey obstacle information to the user. The system has undergone a formative evaluation(More)
In this paper we present a new bimanual markerless gesture interface for 3D full-body motion tracking sensors, such as the Kinect. Our interface uses a probabilistic algorithm to incrementally predict users' intended one-handed and twohanded gestures while they are still being articulated. It supports scale and translation invariant recognition of(More)
Space time cube representation is an information visualization technique where spatiotemporal data points are mapped into a cube. Information visualization researchers have previously argued that space time cube representation is beneficial in revealing complex spatiotemporal patterns in a data set to users. The argument is based on the fact that both time(More)