Dual-Cursor: Improving User Performance and Perceived Usability for Cursor-Based Text Entry on TV Using Remote Control

摘要

Entering text with a general five-key TV remote is a laborious task. A strategy for entering text with two interconnected cursors is proposed, whereby a secondary cursor is employed to maneuver the main cursor through fast-tracks. The main cursor is maneuvered in a 2D full-size onscreen keyboard space, whereas the sub-cursor moves among all predictive candidates in a 1D subspace. Each cursor is operated by a specific interaction method, and the movement of either must be mapped from one to the other. Compared to single-cursor methods, the combination of the main cursor and the sub-cursor operations usually results in fewer manual loadings, even when the target character is out of the prediction list range. A computer simulation based on a corpus of 57258 multimedia titles (in Chinese) demonstrated that the keystrokes per character, powered by a dual-cursor technique, could be predicted to be reduced by 38.6–69.9% with very few predictive candidates for various keyboard layouts (compared with those of conventional non-predictive method). The keyboard layout and the number of candidates were further investigated by means of a usability test. The results revealed that with only 10 min of practice, novice users could achieve a mean text entry speed of 33.3, 29.5 and 22.8 characters per minute for QWERTY, alphabetic square, and alphabetic two-row layouts, respectively, which is 31.6%, 14,.3% and 67.6% faster than the corresponding conventional input method, and is 12.7%, 6.9% and 25.0% faster than the current version of popup dialog method. The dual-cursor can significantly improve perceived usability and offers the potential to be applied to numerous other cursor-based text entry contexts.