Scanning

An input method used in augmentative and alternative communication (AAC) that allows users with severe motor impairments to make selections using one or more switches. The system sequentially highlights items in a vocabulary set, and the user activates a switch when the desired item is highlighted. Techniques such as row-column scanning (selecting a row first, then an item within it) and frequency-based organization can improve access speed, but communication through scanning remains slow — typically not exceeding 15 words per minute compared to around 150 words per minute for typical speech.