Professionals can learn a great deal about young children's emerging language and communication skills by consulting the ones who know the children best: their parents or caregivers. CDIs At A Glance - Age range covered: 30-37 months; Areas screened: Language and communication skills Approximate time for the CDI: Each form generally takes 20-40 minutes to complete and 10-15 minutes to score; Who completes it: Parents or caregivers; professionals score; and Validity and reliability: Numerous studies document the reliability and the validity of the instruments. The CDIs were normed on approximately 1,800 children in three locations, and the Inventarios were normed on more than 2,000 children. Now, with the CDIs professionals can tap into parents' invaluable day-to-day knowledge - and respond to legislation that requires parental input in child evaluations. Top language researchers developed these standardized, parent-completed report designing the forms to focus on current behaviors and salient emergent behaviors that parents can recognize and track. ""CDI III"" is a brief adaptation of the MacArthur Bates CDIs, applicable to children 30-37 months of age.