What is item response theory?

Construct validity is the argument that a score reflects a named idea — working memory, not “being clever in general.” It is built from theory, patterns of correlations, and failed rival explanations. A 20-trial number-Stroop lite can feel like control. Feeling is not a validity coefficient. This site never reports a licensed IQ. Практика — не клинический IQ.

Criterion validity asks whether a score lines up with something you care about that is not the test itself — a later grade, a supervisor rating, or a Wechsler index. Concurrent means measured at the same time; predictive means later. A visual 2-back lite has no published criterion table. It is not an employment screen and not an IQ. Практика — не клинический IQ.

Content validity is whether the item set covers the skill or knowledge you claimed. A spelling test with only the letter Q is a coverage failure. Shape-span lite samples a tiny visuospatial sequence. It does not cover “all spatial intelligence.” Experts, blueprints and reviews build content arguments. A weekend hackathon does not. Практика — не клинический IQ.

A 95% confidence interval is a procedure: if you repeated the study under the same model, 95% of such intervals would cover the parameter. It is not the probability that this one interval magically contains the truth after you saw it. Licensed IQ manuals turn a standard error into a range around a scaled score. Digit-span lite does not. Treat any integer from this site as a toy count. Практика — не клинический IQ.

In a factor analysis of several tests, a general factor (g) can appear. A subtest’s loading says how much it shares that factor in that sample and battery. Matrices often load high; some speeded motor tasks load lower. A loading is not your worth. N-back lite is not a published g-loading table. This site does not output g. Практика — не клинический IQ.