Guide · culture-fair testing
A culture-fair IQ test, online
A culture-fair test tries to measure reasoning without measuring what a person happened to learn: no vocabulary, no school mathematics, no general knowledge. THETIS is built that way. Its puzzles use only shapes, cells, cards, lamps, marbles, rings and boats, and its introduction and rules can be read in English, Spanish or Mandarin.
What makes a test culture-fair
Vocabulary, arithmetic and general knowledge reflect schooling, language and opportunity as much as reasoning. A culture-fair test leaves them out and asks instead for reasoning about material that is new to everyone: figures, patterns and rules that no one has met before the test. Raymond Cattell's Culture Fair Intelligence Test and John C. Raven's Progressive Matrices are the best-known examples of the idea.
The aim is a fair comparison, not a test that culture cannot touch. Familiarity with puzzles and screens still differs between people, so a careful test also explains its formats before it counts anything, and checks on real examinees that people of different backgrounds find each puzzle equally hard.
Fluid, not crystallized. Reasoning with new material is called fluid intelligence; knowledge built up over the years, crystallized intelligence. Culture-fair tests aim at the first. More on fluid intelligence tests.
How THETIS keeps culture out of the score
No words in the puzzles
Eight families of original puzzles: panels that transform, rows of cells, cards and verdicts, machines, lamps, marbles and gates, rings, boats and berths. You need no vocabulary, no school arithmetic and no general knowledge.
Rules in three languages
The introduction and the rules of every family can be read in English, Spanish or Mandarin. The question under each puzzle is short and always of the same few kinds.
The format explained first
A practice module of 16 puzzles, two from each family, with the reasoning explained after every answer, opens every session: the format never decides the score.
Time to think
THETIS is a power test. Each puzzle has a generous clock of 3 to 20 minutes, and how fast you answer within it never changes your score, so reading speed does not count.
Fairness checked on real data
From first attempts, every puzzle family and level is checked for differences by first language and by device (phone, tablet or computer).
A score with its margin
A deviation IQ (SD 15) with its 95% range, the moment you finish, and a certificate anyone can verify. THETIS measures with much the same precision from about IQ 55 to 200.
Questions
Is any IQ test fully culture-fair?
No. Every test asks for something people have met unevenly: abstract puzzles, a screen, the habit of working against a clock. What a careful design can do is keep words, school knowledge and reading speed out of the score, and then check, on real examinees, whether people of different backgrounds answer each puzzle alike. THETIS does both.
Do I need to speak English to take THETIS?
Very little. The puzzles themselves contain no words. The introduction and the rules of every family can be read in English, Spanish or Mandarin; the question under each puzzle stays in English, but it is short and always of the same few kinds, such as “Which panel replaces the question mark?”.
How is the fairness of THETIS checked?
Examinees may give their first language, and the device they use is recorded. From first attempts, each puzzle family and level is checked for differential item functioning by the Mantel–Haenszel procedure: whether people of the same ability but a different first language, or on a different device, find it harder. The technical manual describes the method.
Is a culture-fair score the same as an IQ from a psychologist?
No. THETIS is an unsupervised online test of fluid reasoning with provisional norms. It is not a clinical or diagnostic assessment; for an official score, see a licensed psychologist.
Read also: Fluid intelligence tests · High-range IQ tests · Compare the thirteen tests