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three-parameter model

in item response theory, a model that specifies three parameters affecting an individual’s response to a particular test item: (a) the difficulty level of the item; (b) the discriminating power of the item; and (c) in multiple-choice items, the effect of guessing. The probability of a correct response to the item is held to be a mathematical function of these parameters.

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Psychology term of the day

January 26th 2025

congenital oculomotor apraxia

congenital oculomotor apraxia

a condition, present at birth, in which a child is unable to fixate objects normally (see oculomotor apraxia). It is characterized by the absence of saccades and smooth-pursuit eye movements in the horizontal plane, but vertical eye movements are preserved: Children with this condition are often mistakenly thought to be blind. Between the ages of 4 and 6 months, they develop thrusting, horizontal head movements, sometimes blinking prominently or rubbing their eyelids when they attempt to change fixation. The cause of congenital oculomotor apraxia is unknown, but there is usually an improvement with age.