Glossary category
Adaptive Testing
The statistical machinery that selects useful questions, updates estimates, and represents uncertainty.
Adaptive Question Selection
Adaptive question selection is the rule an adaptive assessment uses to choose the next item from its bank. The algorithm evaluates what is currently uncertain and selects a question expected to improve the estimate while respecting constraints such as content coverage, item exposure, fairness, and maximum test length.
Bayesian Inference
Bayesian inference is a method for updating probabilities when new evidence arrives. An assessment begins with prior probabilities over possible trait values or profiles, evaluates how likely each answer would be under those possibilities, and produces updated posterior probabilities. Repeating this process makes uncertainty explicit as the test progresses.
Computerized Adaptive Testing
Computerized adaptive testing (CAT) is an assessment method in which software selects each next question using the respondent's previous answers and a statistical model. The goal is to ask items that are informative for the current estimate, often reaching useful precision with fewer questions than a fixed-form test.
Entropy
Entropy is a mathematical summary of uncertainty in a probability distribution. In an adaptive personality assessment, entropy is higher when probability is spread across several plausible results and lower when it is concentrated on fewer possibilities. A question can be valuable when its expected answers would reduce entropy.
Information Gain
Information gain measures how much an observation is expected to reduce uncertainty. In adaptive testing, the system can predict the possible answers to each eligible question, estimate the posterior uncertainty after each answer, and choose the question with the greatest average reduction. The actual gain is known only after a response is observed.
Item Response Theory
Item response theory (IRT) is a family of statistical models that links a person's position on an unobserved trait to the probability of particular item responses. Depending on the model, items can differ in location, discrimination, and response behavior. IRT supports score estimation, item analysis, and computerized adaptive testing.
Latent Trait
A latent trait is an unobserved characteristic inferred from patterns in observable responses or behavior. In personality assessment, sociability or conscientiousness may be modeled as latent traits because they cannot be measured directly. A statistical model estimates a person's position using item responses, but the estimate remains conditional on the model, items, and data.