Adaptive and predictive techniques in a communication prosthesis

This paper describes a communication aid and keyboard emulator which has been developed at Dundee University. The device, Predictive Adaptive Lexicon (PAL), exploits the redundancy in natural language to reduce the key pushes or character selections necessary during the composition of text. Word predictions are offered to the user from a dictionary, and if one of these is selected the word is completed by PAL. PAL adapts to the users vocabulary by automatically capturing words which are not already in the dictionary. These will thereafter be offered in prediction lists. A reduction in the number of character inputs necessary to enter any given text of over 50% is possible when using PAL, giving the user a considerable saving in time and effort.