BubbleFlick

Abstract

We propose BubbleFlick, an effective interface for Japanese text entry on smartwatches. While various ideas have been proposed to provide easy and fast text entry for the Latin alphabet, Japanese text entry has additional challenges such as having more than fifty syllabary characters, or kana, to enter and the subsequent kana-kanji conversion, which translates a sequence of the syllabary characters into a standard expression with a mixture of kanji and kana characters. This paper focuses on interfaces for entry of kana syllabary characters. We designed and prototyped three interfaces: 1) Japanese kana syllabary keyboard, 2) Dial&Flick interface, and 3) DualBelts interface. Through a comparative pilot study of the prototypes, we refined the most promising Dial&Flick interface into Bub-bleFlick. BubbleFlick provides the widest possible area for easy flick operations while also leaving an area for editing text. We conducted a 30-day consecutive user study on BubbleFlick in comparison with Google's latest Japanese text-entry method based on a numeric keypad. After thirty days, BubbleFlick showed a text-entry speed of over 35 characters per minute, which was comparable to Google's numeric-keypad-based method for novice participants. Through the user study, Bub-bleFlick showed a lower error rate and gave us informative hints for further improvement.