Glossary
Searchable terminology from accessibility, web standards, and related fields.
12 results found in statistics.
- Click-Time Distribution (Timing Profile, Click Precision)
- A statistical model of when a switch user activates their switch relative to a target timing event, used to characterize the precision and consistency of a user's motor control. In the Nomon interface…
- Cohen's Kappa (Kappa Statistic, Kappa Coefficient)
- A statistical measure of inter-rater reliability that accounts for agreement occurring by chance, used to assess the consistency between two or more raters coding qualitative data. Values range from -…
- Dynamic Bayesian Network (DBN, Temporal Bayesian Network)
- A probabilistic graphical model that represents sequences of variables over time, extending standard Bayesian networks to handle temporal relationships. In accessibility and affective computing contex…
- Gaussian Mixture Model (GMM)
- A Gaussian Mixture Model (GMM) is a probabilistic model that represents data as a weighted combination of multiple Gaussian (normal) distributions. Each component Gaussian has its own mean and covaria…
- Growth mixture model (GMM, Latent class growth model)
- A statistical method that identifies unobserved subpopulations (latent classes) within a dataset based on distinct patterns of change over time. In accessibility research, growth mixture models can re…
- Long Tail (Long-tail Distribution, Long-tail Participation)
- A statistical distribution in which a small number of items or participants account for the majority of the total, while a very long list of lower-frequency items collectively make up the remainder. T…
- Pareto Principle (80/20 Rule, Law of the Vital Few)
- The empirical observation, named after economist Vilfredo Pareto, that in many systems roughly 80% of effects come from 20% of causes. In crowdsourcing and volunteer communities, the principle predict…
- Probabilistic Sampling (Random Sampling, Statistical Sampling)
- A sampling method in which every member of a population has a known, non-zero probability of being selected for the sample. In accessibility evaluation, probabilistic sampling of web pages allows audi…
- Psychometric validation (Psychometric evaluation, Instrument validation)
- The process of establishing that a measurement instrument (such as a questionnaire or scale) possesses adequate reliability (consistency of measurement), criterion validity (correlation with establish…
- Signal Detection Theory (SDT)
- A statistical framework used to measure the accuracy of a system or person in distinguishing between the presence and absence of a target signal amid noise. In accessibility and assistive technology r…
- 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…
- TrueSkill (TrueSkill Bayesian Rating)
- A Bayesian skill-rating algorithm developed at Microsoft Research (Herbrich et al., 2007) that models each player or option as a normal distribution with a mean skill μ and uncertainty σ, updating bot…