Methods, systems, and apparatus, including medium-encoded computer program products, for detection of cheating on a cognitive test. In one aspect, a method includes receiving first information concerning a person, the first information specifying the person's responses, and lack thereof, for items of a cognitive test administered to the person, wherein the cognitive test includes multiple item-recall trials used to assess cognitive impairment; analyzing the first information using a classification algorithm trained on second information concerning a group of people to whom the cognitive test has been administered, the classification algorithm generated in accordance with a first part and a second part, the first part distinguishing between cheaters and non-cheaters, and the second part distinguishing between impaired cheaters and non-impaired cheaters; and identifying, based on the analyzing, the person as a cheater requiring a verification test to confirm an initial result of the cognitive test.