ICAR Intelligence Test (adaptive)

The International Cognitive Ability Resource (ICAR) is a public-domain intelligence test with four kinds of item: number series, verbal reasoning, matrix reasoning and three-dimensional rotation. This is its 60-item pool given as an adaptive test: after each answer the next item is chosen to be the most informative at your estimated level. Each kind gets at least 4 items; the hardest items in the pool are rotation items, so a high scorer meets more of those. You get 20 items, and up to 4 more if the estimate is still imprecise: a good deal more precise than the 16-item short form, in well under half the time of the full 60. Untimed; most people take 10–15 minutes.

Your score is an IQ relative to the SAPA Project sample, about 169,000 online volunteers who answered these items in 2010–17. They chose to take a test online, as you did, and are not a sample of the general population, which scores lower; there is no adjustment for age. The item difficulties come from a two-parameter IRT model fitted to their answers.

Two changes from the original items: the “I don’t know” and “None of these” options are removed everywhere except the rotation items, where “none” can be right, and the letter series are converted to number series (A = 1 … Z = 26). Both make this version slightly easier than the one the difficulties were estimated on, so treat the score as a little generous. The full 60-item test and the 16-item short form use the same items.