Age Equivalents

Synonyms

Mental age; Test age

Definition

Age equivalent scores provide an estimate of the chronological age at which typically developing children demonstrate the skills exhibited by the child being assessed. The age equivalent score is based on the mean raw score on a test obtained by the group of children in the normative sample at a specific age. In simple terms, if on average children at 36 months of age obtain a score of 10 correct responses on a particular test, then any child obtaining a score of 10 correct will receive an age equivalent of 36 months. Age equivalent scores are often expressed in years and months (e.g., 5–0 for 5 years, 0 months).

Though age equivalent scores are appealing in that they appear to provide convenient descriptive information, they can be misleading and do not necessarily represent the level of functioning of the individual. For example, a 3-year-old child who receives an age equivalent of 4–6 on a test of expressive vocabulary is only similar to a...