Scanning System

An assistive technology input method in which selectable items are sequentially highlighted on screen, and the user activates a switch (or other simple input) when the desired item is highlighted. Scanning systems are designed for people with severe motor disabilities who can reliably perform only one or two distinct actions — such as pressing a single switch, sipping/puffing, or blinking. Hierarchical or group scanning improves efficiency by first highlighting groups of items (e.g., rows), then individual items within the selected group, reducing the number of switch activations needed. Key configurable parameters include scanning speed (delay between items), number of scanning cycles before timeout, scanning direction, and auditory/visual feedback. While scanning is slower than direct selection methods, it enables independent computer access for individuals with the most limited motor abilities.