Glossary

Searchable terminology from accessibility, web standards, and related fields.

93 results found in Motor Accessibility.

EyeDraw (Eye Draw)
A software application developed at the University of Oregon that enables people with severe motor impairments, particularly children, to create freehand drawings using eye movements tracked by an eye…
False Activation (Accidental Activation, Unintended Gesture)
An interaction error in gesture-based systems where the system incorrectly interprets a user's resting hand position or unintentional movement as a deliberate input command. In virtual reality, false …
Fitts' Law (Fitts Law)
A predictive model of human movement that describes the time required to move to a target as a function of the target's size and distance from the starting point. Formulated by Paul Fitts in 1954, the…
Form Factor (Device Form Factor, Handset Form Factor)
Form factor refers to the overall physical size, shape, weight, and mechanical configuration of a device — for mobile phones this includes distinctions like candy-bar, clamshell (flip), slide-out keyb…
Fractionation (Finger Fractionation, Finger Independence)
The ability to move individual fingers independently of one another, a key measure of fine motor control assessed in stroke rehabilitation. After a stroke, patients often lose fractionation, meaning t…
Freehand Gesture Interaction (Hand Tracking Interaction, Controller-Free Interaction)
An input method for virtual and mixed reality systems that uses camera-based hand tracking to detect and interpret natural hand movements without requiring physical controllers. Freehand gestures such…
Functional Near-Infrared Imaging (fNIR, fNIRS, Functional Near-Infrared Spectroscopy)
A neuroimaging technique that measures brain activity by detecting changes in oxygenated blood volume using near-infrared light transmitted through the skull. In accessibility contexts, fNIR enables b…
Gait (Walking Pattern, Locomotion Pattern)
The pattern of movement during walking, characterized by measurable parameters including walking velocity, cadence (steps per minute), step length, stride length, step time, cycle time, and swing time…
Gestural Interaction (Gesture-Based Interaction)
A mode of human-computer interaction in which users control systems through movements of the body — hands, arms, head, eyes, or whole body — captured by sensors such as accelerometers, cameras, IMUs, …
Gesture Interaction (Gesture-based interaction, Gestural interfaces)
An input modality in which users control digital systems through hand, arm, or body movements detected by cameras, depth sensors, IMUs, or wearable devices rather than through traditional keyboards, p…
Gesture Recognition Threshold (Activation Threshold, Gesture Detection Threshold)
The predefined parameters that a gesture recognition system uses to determine whether a user's hand movement constitutes a valid gesture input. These thresholds specify requirements such as the exact …
Ghost Cursor (Phantom Cursor, Proxy Cursor)
A visual indicator displayed on screen that shows a potential cursor position, used in speech-based and alternative cursor movement systems. Multiple ghost cursors can be displayed simultaneously, typ…
Goal Crossing (Crossing-Based Input, Crossing Interface)
An input technique where users select targets by moving through a boundary line rather than clicking within a target area. Research shows goal crossing can improve input performance for people with mo…
Gorilla Arm Syndrome (Gorilla Arm, Gorilla Arm Effect)
Fatigue, pain, and discomfort in the arms and shoulders caused by prolonged use of interfaces that require sustained arm elevation without support. The term originates from early touchscreen computing…
Grid-Based Cursor Control (Grid-Based Navigation, Grid Overlay Navigation)
A hands-free cursor positioning technique that overlays a numbered grid on the screen, allowing users to select a cell by voice command or other input to recursively zoom into smaller screen regions u…
Grid-Based Navigation (Grid Navigation, Grid Cursor Control)
A speech-controlled cursor positioning technique that divides the screen into numbered regions, allowing users to select progressively smaller areas by speaking numbers until the cursor reaches the ta…
Hands-Free Interface (Hands-Free Computing, Hands-Free Input)
A hands-free interface is a computer interaction system that does not require the use of hands or fingers, enabling users to control software through alternative input channels such as head movements,…
Head Control (Head-Controlled Interface, Head Mouse, Head Pointer)
An alternative computer input device that translates head movements into cursor movements on screen, enabling people who cannot use their hands or arms to operate a computer. Head control systems typi…
Head Pointing (Head-Controlled Pointing, Head Mouse)
Head pointing is an alternative input method that maps head movements to cursor position on a computer screen, enabling hands-free mouse control. The user moves their head to direct the cursor, with t…
Heisenberg Effect (Heisenberg Problem)
In human-computer interaction, a spatial interaction problem where the act of making a selection disrupts the positional accuracy of the cursor or pointer. In virtual reality freehand gesture contexts…