A theoretical framework used to explain how people detect meaningful stimuli under uncertain conditions.
Signal Detection Theory
The meaningful stimulus that a person attempts to detect in a detection task.
Signal
Background interference that makes detecting the target stimulus difficult.
Noise
The outcome in which a signal is present and the observer correctly identifies it.
Hit
The outcome in which a signal is present but the observer fails to detect it.
Miss
The outcome in which no signal is present but the observer reports that one exists.
False Alarm
The outcome in which no signal is present and the observer correctly identifies its absence.
Correct Rejection
The measure representing the ability to distinguish signals from background interference.
Response Criterion
The threshold or rule used by a decision-maker to determine whether a signal is present.
optimum Response criterion
The statistical indicator that reflects whether a decision strategy is conservative or liberal.
optimum Response criterion
The ability to maintain attention and detect rare signals over a long monitoring period.
vigilance
The reduction in detection performance that occurs during prolonged monitoring tasks.
vigilance decrement
The process of identifying the magnitude of a stimulus without comparing it to other stimuli.
absolute judgement
A theory that quantifies the transmission and processing of information in communication systems.
Information theory
The field that studies how users interact with technology by integrating computer science, cognitive science, and human factors engineering.
Human Computer Interaction
The psychological principle suggesting that humans can reliably distinguish only about 5–9 stimulus categories.
Miller’s Law
The visual and interactive elements of a system through which users communicate with a computer.
User Interface
The overall perception, satisfaction, and experience of users when interacting with a product or system.
User Experience
A 10-item questionnaire widely used to measure the overall usability of a system.
System Usability Scale
A usability evaluation tool that measures satisfaction with software aspects such as screen layout, terminology, and system capabilities.
Questionnaire for User Interface Satisfaction
A measurement approach derived from the Technology Acceptance Model that evaluates how useful and easy a technology is perceived to be.
Perceived Usefulness and Ease of Use
A standardized questionnaire that evaluates software usability, including emotional reaction, learnability, and system control.
Software Usability Measurement Inventory
A usability evaluation questionnaire based on ISO 9241 ergonomic standards for human-computer interaction.
Iso Norm
A questionnaire administered after usability testing to measure system usefulness, information quality, and interface quality.
Post Study System Usability Questionnaire
