Frequency of Hebrew word usage by children with intellectual and developmental disabilities: implications for AAC core vocabulary.

Appropriate vocabulary selection for augmentative and alternative communication (AAC) intervention is crucial to support communication and language development in children with intellectual and developmental disabilities (IDD). Core vocabulary lists are commonly used to guide this process, and there is a need for language-specific consideration. This paper aimed to develop a wordlist for selecting the core vocabulary for AAC intervention for young Hebrew-speaking children with IDD. Five children (age 3;5-8;4) were audio-recorded in naturalistic interactions with an interviewer and family members. Using Levy's clinical corpus in the Child Language Data Exchange System (CHILDES) and Child Phonology Analyzer (CPA) tools and preestablished codes, wordlists with usage frequencies were extracted and coded for lexeme, lexical categories and functions or content. The percentages of the 20, 50, 100, and 200 most frequent lexemes were calculated for each child and for the five children combined. The top 200 most frequently used lexemes constituted 85% of the composite lexicon. A comparison was made between this study list and a previous list derived from language samples of typically developing (TD). Lexemes representing function words dominated, albeit with a slight preference for content words in children with IDD. Among the content words, children with IDD used more adverbs, while children with TD used more verbs. Implications for AAC core vocabulary are discussed.