Optimisation of the Selection Set Features for Scanning Text Input

Scanning is one of the most popular text input methods for people with severe movement restrictions due to diverse kinds of disabilities. It is frequently used to input messages into communication systems, such as text-to-voice translators in order to maintain conversations. Nevertheless, the rate of text production usually obtained is very slow. For this reason, every effort to save time and optimize communication speed is welcome. In this way, this paper presents a study on the influence on the character input rate of diverse parameters related to the matrix that contains the selection set, such as shape, size, number of dimensions and layout of the selectable items. Its purpose is to extract a set of guidelines to design efficient input systems well adapted to the user, based on the scanning of items and its selection by means of one switch or push-button.