ABSTRACT
PURPOSE: Selecting vocabulary for preliterate individuals who use augmentative and alternative communication presents multiple challenges, as the number of symbols provided must be balanced with cognitive, motoric, and other needs. Prioritizing certain types of vocabulary thus becomes a necessity. For example, prioritizing core vocabulary-that is, words that are commonly used across a group of people and contexts-is a common practice that attempts to address some of these issues. However, most core vocabulary research to date has narrowly focused on individual word counts, ignoring other critical aspects of language development such as how vocabulary aligns with typical development and how children use core and fringe vocabulary within their utterances. METHOD: Descriptive and inferential statistics were used to analyze 112 transcripts to describe how typically developing toddlers (aged 2.5 years) use core and fringe vocabulary within their utterances, in reference to a range of commonly used core vocabulary lists. RESULTS: Results indicated that the proportion of the toddlers' utterances that consisted of only core, only fringe, or core + fringe vocabulary varied dramatically depending on the size of the core vocabulary list used, with smaller core lists yielding few "core-only" utterances. Furthermore, utterances containing both core and fringe vocabulary were both grammatically and semantically superior to utterances containing only core or only fringe vocabulary, as evidenced by measures such as mean length of utterance and total number of words. CONCLUSION: Thus, relying on word frequency counts is an insufficient basis for selecting vocabulary for aided preliterate communicators.
