Test types
IQ tests, one at a time
People use “IQ test” for at least eight unrelated instruments. Each has a different purpose, a different format and a different amount of evidence behind it.
If you are not sure which one applies to you, the short version: a result that has to count anywhere comes from an individually administered test given by a psychologist. Everything else on this page is either a screening instrument, a research tool or a curiosity. The overview of the families explains how they fit together.
Everything in this section
The Mensa IQ test
The 98th-percentile requirement, the two routes in, and why no online test qualifies anyone.
Read more →Raven's Progressive Matrices
The archetypal non-verbal test, the six rule families its items are built from, and the limits of culture-fair.
Read more →WAIS — the adult standard
What a psychologist does across a two-hour session, what the index scores mean, and why no website offers one.
Read more →WISC — the children's test
The instrument behind most gifted and special-education decisions, and how to read the report.
Read more →The Wonderlic test
Fifty questions in twelve minutes, the score conversion table, and why pacing beats difficulty.
Read more →The CogAT
The group test schools run first, the three batteries, and what the profile codes actually tell a parent.
Read more →The Stanford–Binet
The oldest test still in use, its five factors in verbal and non-verbal modes, and where the huge historical scores came from.
Read more →Culture fair tests
Cattell's instrument, the 24-point standard deviation that confuses everyone, and what culture-fair does not mean.
Read more →Start with your own result
Ten questions, no sign-up, and a band rather than an invented number.