Glossary

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

33 results found in evaluation.

Response Bias (Acquiescence Bias, Yea-Saying Bias)
A systematic tendency for research participants to respond in a particular way regardless of the actual content of the question, distorting data collection and analysis. In accessibility research invo…
SUS (System Usability Scale)
Abbreviation for System Usability Scale, a ten-item questionnaire developed by John Brooke in 1986 that produces a single usability score from 0 to 100 based on user ratings of agreement with statemen…
Semantic distance (Semantic similarity, Word embedding distance)
A computational measure of how different two words are in meaning, typically derived from word embedding models like word2vec that represent words as vectors in a high-dimensional space. In caption ev…
Single-case experimental design (SCED, N-of-1 design, ABAB design)
A rigorous research methodology that evaluates intervention effects by systematically alternating between baseline and treatment conditions within individual participants, using each person as their o…
Spearman correlation (Spearman rank correlation, Spearman's rho)
A non-parametric statistical measure of the strength and direction of the monotonic relationship between two ranked variables, ranging from -1 to +1. In accessibility evaluation research, Spearman cor…
Summative Evaluation (Summative Usability Testing, Summative Assessment)
Usability evaluation conducted on functional software or high-fidelity prototypes, typically later in the development process, to measure the effectiveness of specific design choices. Summative testin…
System Usability Scale (SUS)
A widely used 10-item Likert scale questionnaire developed by John Brooke in 1996 that provides a quick, reliable measure of perceived usability. Scores range from 0 to 100, with higher scores indicat…
Tactile Accuracy
Tactile accuracy is an evaluation criterion for measuring how well a person perceives the shape information of an object in a tactile image through touch. Unlike "naming accuracy" (whether someone can…
Upper Baseline (Gold Standard, Reference Standard)
In accessibility evaluation research, an upper baseline is a high-quality reference stimulus used to establish the best achievable performance against which other systems are compared. For sign langua…
Video intelligibility (Signal intelligibility, Visual signal clarity)
The degree to which a video signal can be perceived and understood by the viewer, determined by technical parameters including frame rate, bit rate, spatial resolution, and codec quality. Video intell…
Wizard-of-Oz study (WoZ study, Wizard of Oz method)
A research methodology in which participants interact with a system they believe is automated, but which is actually operated partially or fully by a hidden human operator (the "wizard"). This approac…
Word error rate (WER)
The standard metric for evaluating automatic speech recognition accuracy, calculated as the number of substitutions, deletions, and insertions divided by the total number of words in the reference tra…
Word importance (Lexical importance, Information content)
A measure of how critical a specific word is to the overall meaning of a sentence, typically computed using neural language models that estimate how predictable a word is from its context. In captioni…