Parent Certainty and Consistency When Completing Vocabulary Checklists in Young Autistic Children

Purpose: Using a novel parent report measure, this study investigated whether asking parents to rate their certainty when reporting on child vocabulary skills provided additional insight into parent report and emerging language abilities in young autistic children. Specifically, we investigated whether parent certainty varied based on whether the child was reported to understand, understand and say, or neither understand nor say the word and whether standardized measures of expressive and receptive language abilities and/or autistic traits predicted parent certainty. Lastly, we investigated whether certainty was associated with inconsistency in parent report of child word knowledge. Method: Twenty-one parents and their autistic children ages 2-5 years participated. One parent per child completed the MacArthur-Bates Communicative Development Inventories (MCDI) Words and Gestures form and a custom vocabulary checklist including 24 object nouns from the MCDI. Within the custom form, parents indicated whether their child understood, understood and said, or neither understood nor said 24 target nouns and reported how certain they were about their responses using a 5-point scale. Expressive language, receptive language, and autistic traits were measured via direct assessment using standardized measures. Results: Parent certainty varied widely and was higher for words the parents reported the children understood and said compared to that for words children either understood or neither understood nor said. Certainty ratings were higher when a child had higher standardized receptive and expressive language scores. Lastly, parent certainty was associated with reporting consistency, clarifying previous findings of inconsistencies in parent report of child vocabulary. Conclusion: Findings from this study indicate that measuring parent certainty provides critical information when assessing early vocabulary skills in autistic children.