The MacArthur Communicative Development Inventories (the CDI/Infants and the CDI/Toddlers) have been developed by Fenson, Dale, Reznick, Thal, Bates, Hartung, Pethick, and Reilly (1993) in U.S.A. as an instrument to assess the gestural and language development for infants and toddlers. They provide an efficient and valid means of assessing a wide range of language-based skills in infants and toddlers from parent's reports. There is a large body of evidence supporting the reliability, validity, clinical utility and research potential of the MacArthur Communicative Development Inventories. Currently, versions of the Communicative Development Inventories are available for Spanish (Jackson-Maldonado, Thal, Bates, & Gutierrez-Clellen, 1993), for Italian (Camaioni, Caselli, Logobardi, & Volterra, 1991; Caselli & Casadio, 1993), and for American Sign Language (Reilly, Provine, & Bellugi, 1993).
In Japan we do not have a good instrument to assess language-based skiils for infants and toddlers. We use developmental tests to assess them. They have few language items for infants and toddlers. For example Kyoto Scale of Psychological Development provides only five language items for the age of 12-24 months. It will be valuable to develop a Japanese version of the MacArthur Communicative Development Inventory which is suited to Japanese customs and culture.
In this report the following issues will be reported.
(1) The establishment of the Japanese Early Communicative Development Inventory
(2) The major developmental trends and variability
(3) Comparisons within our data
A. The comparison of baby-words with adult-words
B. Sex differences
C. The differences between home-reared children and day-care children
D. Intercorrelations among the language and gestures
(4) Future plans