Scanning Rate

The speed at which options in a scanning interface are sequentially highlighted, typically measured in seconds per item. The scanning rate is a critical configuration parameter in switch-access systems — too fast and the user cannot react in time to make a selection, too slow and interaction becomes frustratingly time-consuming. Optimal scanning rate depends on the user's motor response time, cognitive processing speed, and the specific input method being used. Clinicians set the scanning rate during assistive technology assessment, and it may need adjustment over time as the user's abilities change or as they become more proficient with the system.