A Usability Study of the Central-Bantu Multilingual Keyboards

Central-Bantu speakers usually use the predominant QWERTY keyboard on a combination of some local and European languages, such as Chichewa and English. There has been no research that looks into usability issues of Central-Bantu speakers typing text in English and in local languages on QWERTY. This article presents our experiments that assess the usability of multilingual keyboards for Central-Bantu language speakers. We first obtained a Central-Bantu layout that is partially optimized from QWERTY, based on the German-QWERTZ keyboard, and a highly optimized version based on the French-AZERTY keyboard. The two keyboard layouts (Entry and advanced-level) were optimized for both English and Chichewa, for a two-finger text-entry mode. Simulation tests measured text-entry rates for Chichewa and English. The usability experiments show that the text-entry rate of English is about 13% higher than that of Chichewa, which is close to the prediction of the simulation test. The Bantu keyboards reduced this imbalance to about 4%. While the simulation tests predicted an increase in text-entry rate, the experimental tests show a decrease in performance. Typing-error rates almost double from QWERTY to the Advanced-Bantu keyboard. In this study, we show that the Central-Bantu keyboards have high practical-performance potential for both Chichewa and English, at balanced usability levels.