Glossary

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

25 results found in Human Factors.

Age-related Differences (Age Effects, Generational Differences)
The systematic variations in technology use, learning strategies, and task performance that occur across different age groups. Research consistently shows older adults take 1.5 to 2 times longer than …
Attention Tunneling (Visual Tunneling, Attentional Tunneling, Cognitive Tunneling)
A phenomenon in which a user concentrates so narrowly on a primary information source - typically a visual overlay, head-up display, or instrument - that they fail to notice relevant events, objects, …
Background Noise (Ambient noise, Environmental noise)
The sum of unwanted or competing sound in an environment — traffic, construction, conversation, HVAC systems, weather — that is present alongside a signal of interest. Background noise is characterize…
Cognitive Cycle (Cognitive Processing Time, Cognitive Response Time)
In the Model Human Processor framework, the cognitive cycle represents the time required for a person to process perceived information and make a decision about how to respond. A single cognitive cycl…
Computer Literacy (Digital Literacy, Technology Literacy, ICT Literacy)
A person's knowledge and ability to use computers and digital technology effectively. In accessibility research, computer literacy is an important variable when studying how different user groups inte…
Ergonomics (Human factors engineering)
The scientific discipline concerned with understanding interactions between humans and other elements of a system, and the profession that applies theory, principles, data, and methods to design in or…
Fovea (Foveal Vision, Fovea Centralis)
The small, central area of the retina responsible for sharp, detailed vision, covering approximately 1 degree of visual angle. The fovea contains the highest density of cone photoreceptors and provide…
Gorilla Arm (Gorilla-arm effect, Gorilla arm syndrome)
A well-documented ergonomic phenomenon in which sustained unsupported arm elevation — typical of mid-air touchscreen, vertical display, or extended reality (XR) gesture interaction — produces rapid sh…
Hierarchical Task Analysis (HTA)
A structured method for describing and analyzing tasks by breaking them down into goals, sub-goals, and operations in a hierarchical tree structure. Originally developed for industrial and safety-crit…
Human Failure Modes and Effects Analysis (HFMEA, Human FMEA)
An adaptation of Failure Modes and Effects Analysis (FMEA) that focuses specifically on human performance and error. HFMEA systematically examines each step in a process to identify how humans might f…
Kinesthetics (Kinaesthetics, Kinesthesia, Kinesthetic sense)
The sense of body position, movement, and muscular effort derived from receptors in muscles, tendons, and joints. Kinesthetics is closely related to — and often used interchangeably with — propriocept…
Mental Workload (Cognitive Load, Cognitive Workload)
The amount of cognitive effort and mental resources required to complete a task. In accessibility contexts, mental workload is an important measure of how demanding an interface is to use — an interfa…
Motor Function Time (Motor Response Time, Motor Cycle Time)
The time required to execute a physical action such as pressing or releasing a key, clicking a mouse button, or moving a pointing device. In the Model Human Processor, motor function time for able-bod…
Motor Skills (Motor Abilities, Motor Function)
The learned abilities to perform movements with accuracy, speed, and coordination. Motor skills are typically divided into gross motor skills (large muscle movements like walking, jumping, balance) an…
Muscle Fatigue (Motor fatigue)
A decline in the capacity of a muscle or muscle group to generate force or sustain activity after prolonged or repeated exertion. In human-computer interaction, muscle fatigue is a central concern for…
Occlusion (Hand Occlusion, Finger Occlusion, Visual Occlusion)
In the context of touchscreen and pen-based interaction, occlusion refers to the user's hand or finger blocking their view of content on the screen while interacting with it. Occlusion is a significan…
Overshoot (Cursor Overshoot, Target Overshoot)
In pointing device interaction, the phenomenon where the cursor travels beyond the intended target before the user can stop it, requiring corrective movements back toward the target. Overshoot is meas…
Perceptual Cycle (Perceptual Response Time, Perceptual Processing)
In the Model Human Processor framework, the perceptual cycle is the time required for a person to perceive and register a stimulus from their environment, such as seeing a visual change on screen. The…
Psychophysics
Psychophysics is the scientific study of the quantitative relationship between physical stimuli and the sensations and perceptions they produce. Founded in the 19th century, it uses rigorous experimen…
Satisficing
A decision-making strategy where users select the first option that appears "good enough" rather than evaluating all possibilities to find the optimal choice. Coined by Herbert Simon, satisficing is c…