Stroke++: A new Chinese input method for touch screen mobile phones

• Extract 42 Chinese radicals from 200 000 SMSs.
• Manually decompose 6763 Chinese characters into radicals.
• Developed Stroke++ to input Chinese using radicals.
• Stroke++ is a competitive Chinese text entry method.

Over the past few decades, users have been feeling clumsy inputting Chinese on mobile devices, partly because the layout of the keyboard/keypad is originally designed for inputting Latin alphabets. To improve this user experience, we propose Stroke++, a novel Chinese input method for touch screen mobile devices. More specifically, Stroke++ provides efficient keypad layout, a friendly user interface and a intelligent character/phrase candidate set generation algorithms. Stroke++ splits a Chinese character into multiple radicals. By leveraging hieroglyphic properties of Chinese characters, our method requires users to only input a subset of the radicals to identify the target character, making it much faster and easier to input Chinese on mobile phones. Our user study results show that Stroke++ outperforms most major Chinese input methods on mobile devices, including Stroke, Pinyin and Hand Writing Recognition (HWR), in terms of the input efficiency and usability. Moreover, we also demonstrate that Stroke++ offers a low entry barrier for Chinese-input novices.