The Italian MB-CDI 'Words and Gestures' complete and short form: Normative data and validity

This study compares normative data of the Italian Words and Gestures complete form (WG CF) and short form (WG SF) of the MacArthur-Bates Communicative Development Inventories (MB-CDI). The samples included 648 children for the WG CF and 583 children for the WG-SF designed for children aged 8-24 months. The concordance between WG SF and WG CF is analyzed in a subgroup of 66 children. Results revealed very close developmental trends as assessed through the two forms, and strong correlations between action/gesture production, word comprehension and word production. The two forms showed high concurrent validity with Intra-Class-Correlation coefficients higher than 0.70, suggesting that the two forms may be used interchangeably in order to describe early communicative and linguistic development in children up to 24 months of age, paying particular attention of saturation of the short form in assessing action-gesture production.