Keypad for Large Letter-Set Languages and Small Touch-Screen Devices (Case Study: Urdu)

Composing Urdu is a thorny task on touch-screen devices particularly handheld modern devices such as smart phones and PDAs. Design and development of optimal keypad for Urdu composing is complicated due to its relatively large letter-set. Conventional QWERTY replica keypad has migrated from computers to small screen devices. The multitap T9 keypads are also in use. These have raised grave issues in composing Urdu text on small touch-screen devices. Last but not the least, health concerns have been ignored in development of input systems for Urdu and other languages with large letter-sets. We developed a novel keypad for Urdu that has been optimized for accurate, easy, speedy and efficient typing on small touch-screen handheld gadgets. We carefully designed our proposed keypad so that it offers better visibility, usability, extendibility, aesthetics and user friendliness. We also took the users’ health issues into account at the design time of our suggested keypad. The evaluation through applying automated procedures, our proposed keypad showed improvement by 52.62% over the existing keypads. In addition to automated procedures, we carried out the users evaluation for real world performance comparison between our proposed keypad and in-the-market generic keypads. Our proposed keypad is optimized for Urdu. However it is applicable to Arabic, Persian, Punjabi and other Perso-Arabic script languages. With minor changes in the backend script settings, our proposed keypad is applicable to non-Perso-Arabic script languages with larger letter-sets e.g. Hindi etc.