Ergonomics Study On Thumb-based Chinese Mobile Keyboard Layout

Keyboard input based on thumb operation in the present as well as the future will be irreplaceably used as an input mode in Chinese text entry on mobile phones, and the efficiency of Chinese mobile keyboard text input has become one of important symbols weighting the level of mobile products' usability.This study applied engineering psychology method to explore the text input characteristics of users operating mobile keyboard with the thumb, and to identify the layout factors of influencing performance based on thumb operation And then, according to the thumb operation characteristic model and the phonetic alphabets frequency relational model, established a new phonetic text input method by changing the phonetic alphabets' arrangement order ,and comparing with the original text input method, inquire into the user's thumb operation performance of Chinese text input in the different mobile keyboard layouts.This research mainly included three study series, the first one was mainly to explore the text input characteristics of users operating mobile keyboard with the thumb, and to identify the layout factors of influencing performance based on thumb operation. The second one was mainly focused on discussing the frequency relationship of the Chinese characters letters in the current Chinese inputs, and had established the commonly used Chinese phonetic alphabet frequency model and Chinese mobile phone text messages letter frequency model. In the last one, in accordance with the thumb operation characteristic model and the phonetic alphabets frequency relational model, we established two new mobile phone keyboard layouts through changing the phonetic alphabets' arrangement order, and in comparison with the existing mobile keyboard layout, explore the user's thumb operation performance of Chinese text input in the different mobile phone keyboard layouts.The following conclusions had been drawn in this study: 1. Keys' position on the mobile keyboard has a significant effect on the operation performance. For standard mobile keyboard, the "5" key's performance is the best; and for right-handed participants, the operation performance of keys in the upper-left keyboard region is superior to that of other regions.2. When the two connect enter the letters in the same keys, enter their best performance, followed by the adjacent keys. At the same time, the adjacent key's performance located at horizontal and vertical directions is better than that of the diagonal distribution. When the two connected in the letters do not enter the adjacent keys, enter its worst performance:3.In terms of the occurrence frequency of the commonly used Chinese phonetic first letter as well as the occurrence probability of the first two connection letters, the letters' distribution on the mobile keyboard can be carried on the following grouping: SZH,JXYI,DEA (N),WO (U),BGU,M (E) L;4. According to the occurrence frequency of the commonly used mobile text messages' first letter and the occurrence probability of the first two connection letters , the letters' distribution on the mobile keyboard can be carried on the following grouping: ZSH,DBA (N),JXIY,LME,WO (U);5. Compared with the traditional keyboard layout of the mobile phone, the participants' performance operating the mobile phone that the keyboard layout is based on thumb-operated characteristic and the Chinese phonetic alphabets frequency characteristic, is higher. The improved key layout has superiority and more practical value than the traditional key layout.