This popular diagnostic test evaluates and quantifies communication skills of normal and developmentally delayed children functioning between 4 and 48 months.

It has two major sections: Receptive, which includes behavioral items that test sound and speech discrimination, awareness, and understanding; and Expressive, which includes three types of behavior (imitating, initiating, and responding), as well as two distinct areas of expressive measurement (length and grammatical and syntactic structures of verbal output and articulation).

Age-level norms, from a sample of 252 normally developing children, are provided for both receptive and expressive language. Based on this sample, SICD items were grouped into sets graded at 4-month intervals between 4 and 48 months. The percentage of correct responses for each of these age-graded sets is used to determine the child's Receptive Communication Age and Expressive Communication Age. The resulting behavioral and processing profiles are helpful in developing individualized remedial programs for children.

The inventory is individually administered, usually in 30 to 75 minutes. The Test Manual documents validity and reliability, and the Instruction Manual presents administration directions.