Optimizing a Personalized Cellphone Keypad

Current layouts for alphabetic input on mobile phone keypads are inefficient. We propose a genetic algorithm (GA) to find a suitable keypad layout for each user, based on their personal text history. It incorporates codes for frequent multigrams. We optimize for two-thumb use, minimizing the number of strokes, and consecutive use of the same key or the same hand. Using these criteria, the algorithm re-arranges the characters on a 10-key pad. We demonstrate that this arrangement can generate a more effective layout, especially for SMS-style messages. Substantial savings are verified by computational analysis.