Bayley scale

The Bayley Scale assesses the development of children under age 4 in five domains: cognitive, language (receptive and expressive), motor (gross and fine), social-emotional and adaptive.

The scale is based on the assessment of the interaction between the child and the examiner and observations in a series of tasks. It includes a motor score and fine and gross motor subtest scores. The standardized mean motor score is 100 (SD 15), with scores below 85 indicating mild impairment and below 70 indicating moderate or severe impairment.