The MacArthur Communicative Development Inventories (CDIs) are a pair of widely used
parent-report instruments for assessing communicative skills in infants and toddlers. This report
describes short-form versions of the CDIs and their development, summarizes newly available
normative data and psychometric properties of the instruments, and discusses research and
clinical applications. The infant short form (Level I, for 8- to 18-month-olds) contains an
89-word checklist for vocabulary comprehension and production. The two parallel versions of
the toddler short form (Level II, Forms A and B, for 16- to 30-month-olds) each contain a
100-word vocabulary production checklist and a question about word combinations. The forms
may also be useful with developmentally delayed children beyond the specified age ranges.
Copies of the short forms and the normative tables appear in the appendices.