The BSID consists of three main subscales: Cognitive, Language, and Motor. Each subscale includes a series of tasks that the infant is asked to perform. The Cognitive Scale assesses problem-solving and memory skills, the Language Scale evaluates understanding and use of language, and the Motor Scale measures fine and gross motor skills. The assessment is usually conducted by a trained clinician or psychologist in a controlled setting. The results are then compared to normative data to determine the infant's developmental level.
