Glossary
Psychometrics
Definition
Psychometrics is the field that designs, scores and evaluates psychological tests, including IQ tests, personality questionnaires and aptitude tests. It uses statistics to check whether a test is consistent, whether it measures what it claims, and how to turn answers into fair scores.
Want your own number? The test is 25 visual puzzles, about 12 minutes, no sign-up.
Why it matters for IQ scores
Everything that turns a set of answers into a meaningful IQ is psychometrics: choosing items, setting their difficulty, norming against a reference group, checking reliability and gathering evidence of validity. Early milestones include Spearman's 1904 paper on general intelligence (Wikipedia: g factor) and the Binet-Simon test of 1905 (Wikipedia: Intelligence quotient).
An example: two scoring approaches
Classical test theory adds up right answers into a raw score and compares it with norms. Item response theory models each item's difficulty and estimates ability from the pattern of answers. IQ Octopus uses the second approach, a Rasch model, because its puzzles are generated fresh for each attempt, so two people never see the same 25 items.
Common confusions
Psychometrics is a method, not a verdict. A test built with careful psychometrics still has error, and the same tools that support a score also show its limits. For how this plays out on our test, see how the test works and how online IQ tests work.
Try one · Spatial Reasoning
Which option is the same shape, only rotated?
Tap the option you think is right, or show the answer.
Show the answer
Option 3 is the original figure turned a quarter turn counterclockwise.
How to solve it
- Pick a landmark: the marked cell or the end of the longest arm.
- Turn the figure in your head and watch where that landmark goes, and which side the other cells end up on.
- Turning the figure a quarter turn counterclockwise gives option 3.
- Each of the other options is a mirror image: flipping it over would match, but no turn does.
That was 1 puzzle. The full test has 25.
Sources
- Intelligence quotient. Wikipedia. en.wikipedia.org/wiki/Intelligence_quotient
- g factor (psychometrics). Wikipedia. en.wikipedia.org/wiki/G_factor_(psychometrics)