The MacArthur-Bates Communicative Development Inventories (MB-CDIs)

are parent report instruments which capture important information about children's developing abilities in early language, including vocabulary comprehension, production, gestures, and grammar.


The long forms of the MacArthur-Bates CDIs in English and Spanish are generally appropriate for use with children 8-30 months. Short form versions in both languages are also available, including a short-form extension for use with English-learning children up to 36 months.


The CDI Scoring program is a free, downloadable Windows-based database application (Access, Word, Excel) which enables users to track CDI administrations, score responses, look-up percentiles, and generate user-friendly summary reports.


Adaptations of the CDIs have been developed in nearly 100 languages other than English and Mexican Spanish, following guidelines provided by the CDI Advisory Board. Click below for a list of available languages and currently available contact information.

Young girl

Wordbank compiles responses from many different CDI administrations in dozens of languages, providing exciting new resources for the construction of crosslinguistic lexical norms. Click below to learn about our latest developments!