Mobile Phone Keypad Design for Fast Chinese Text Entry by Phonetic Spelling

The trend of using text messaging on mobile phones has grown rapidly in the last decade. However, mapping the alphabet to twelve phone keys introduces challenging ambiguities for text entry. This challenge is exacerbated in Chinese by the large phonetic alphabet and homophonic Chinese characters. In response, we propose a novel algorithm to generate keypad layouts that reduce ambiguity for Chinese text entry. The layouts may greatly facilitate text messaging for Chinese users. Furthermore, the algorithm can also be applied to layout design for other ideographic languages (such as Korean and Japanese) and English T9 style entry. The solution begins with a metric loosely based on Hick's Law to model and evaluate a keypad layout, estimating a user’s performance time. Then a best-improvement, random-restart local search is used to generate high quality layouts according to the evaluation metric. Although we have not yet performed user studies, we outline a user study plan to compare the resulting layouts against successful commercial layouts. In addition, there are some alternative ideas not implemented. In relevant sections, we will discuss alternatives to the design choices we made, some of which are promising for future work.