PURPOSE: The MacArthur-Bates Communicative Development Inventories are widely used to study early language and communicative development. We recently developed a Spanish version for children with Down syndrome (the CDI-Down) adapted to their particular profile of linguistic and communicative development. The principal aims of this study are to assess the concurrent validity and test-retest reliability of the vocabulary section of this adaptation. METHOD: Validation for productive vocabulary (Study 1) was achieved by correlating CDI-Down scores on expressive vocabulary and measures on the basis of spontaneous speech samples (n = 29). Validation for receptive vocabulary (Study 2) was achieved by correlating CDI-Down scores on receptive vocabulary and measures derived from language items of the Brunet-Lézine Scale (Josse, 1997; n = 70). Reliability (Study 3) was measured with a subset of parents who completed the same inventory 4 months after the original sampling (n = 26). RESULTS: CDI-Down expressive and receptive vocabulary scores showed a significant positive relationship with their comparison measures, thereby demonstrating convergent validity. A significant positive relationship was also found between test-retest measures for productive and receptive vocabularies, thus supporting the reliability of the adaptation. CONCLUSION: The results demonstrate that the CDI-Down is a valid and reliable tool that could be useful for parents, teachers, clinicians, and researchers.
PURPOSE: The MacArthur-Bates Communicative Development Inventories are widely used to study early language and communicative development. We recently developed a Spanish version for children with Down syndrome (the CDI-Down) adapted to their particular profile of linguistic and communicative development. The principal aims of this study are to assess the concurrent validity and test-retest reliability of the vocabulary section of this adaptation. METHOD: Validation for productive vocabulary (Study 1) was achieved by correlating CDI-Down scores on expressive vocabulary and measures on the basis of spontaneous speech samples (n = 29). Validation for receptive vocabulary (Study 2) was achieved by correlating CDI-Down scores on receptive vocabulary and measures derived from language items of the Brunet-Lézine Scale (Josse, 1997; n = 70). Reliability (Study 3) was measured with a subset of parents who completed the same inventory 4 months after the original sampling (n = 26). RESULTS: CDI-Down expressive and receptive vocabulary scores showed a significant positive relationship with their comparison measures, thereby demonstrating convergent validity. A significant positive relationship was also found between test-retest measures for productive and receptive vocabularies, thus supporting the reliability of the adaptation. CONCLUSION: The results demonstrate that the CDI-Down is a valid and reliable tool that could be useful for parents, teachers, clinicians, and researchers.