Transfer Function

A mathematical function that defines the relationship between an input signal and an output response in a control system. In assistive technology and pointer control, a transfer function determines how physical movements (such as head movements, eye gaze, or joystick input) are translated into cursor movements on screen. The design of the transfer function is critical for accessibility because it must account for the specific motor capabilities of the user — for example, dampening involuntary spastic movements while still responding to intentional ones. Well-designed transfer functions can significantly improve pointing accuracy, speed, and user satisfaction for people using alternative input devices.