A prototype scanning system with an ambiguous keyboard and a predictive disambiguation algorithm

This paper presents a prototype single-switch scanning system with a four-key ambiguous keyboard. The keyboard consists of only three keys for letters and an additional key for editing and extra functions. The letter-to-key assignment is based on the shapes of lowercase consonants, and vowels are alphabetically distributed among the keys. An adaptation of the "one-key with disambiguation" algorithm has been used to increase text entry speed. The system has been implemented for Spanish language.