PinyinPie: A Pie Menu Augmented Soft Keyboard for Chinese Pinyin Input Methods

摘要

Soft keyboard for Chinese pinyin input methods are rarely studied although it is one of the default methods on devices with touch screens. Via an analysis of the digraph frequency of the pinyin system, we discovered a unique characteristic of the pinyin system: only 10 Roman letters are needed for the subsequent characters in a pinyin syllable after the leading letter. Making use of this feature and existing knowledge on layout optimization of soft keyboard, pie menu and ShapeWriter, we designed a pie menu augmented keyboard. We conducted a user study to compare user performance to test if the pie menu can help to increase user performance with a working prototype. We found that after about 2 hours' use of the pie menu augmented quasi-QWERTY keyboard, users can reach a speed of 25 Chinese characters per minute with slightly lower error rate. Moreover, users can well remember the layout of the pie menu after about two hours' use of it.