Purpose: This study was designed to test the incremental validity of more expensive vocal development variables relative to less expensive variables for predicting later expressive language in children with autism spectrum disorder (ASD). We devote particular attention to the added value of coding the quality of vocalizations over the quantity of…

This study examined an insufficiently studied predictor of functional language, social motivation, in a group of 87 young children with autism spectrum disorder. Participants (age 14-31 months at the start of the study) were assessed at four times over 24 months. We tested total and indirect associations between early social motivation and later…

Intentional communication has previously been identified as a value-added predictor of expressive language in preverbal preschoolers with autism spectrum disorder. In the present study, we sought to identify value-added predictors of intentional communication. Of five theoretically-motivated putative predictors of intentional communication…

We examined direct and indirect paths involving receptive vocabulary and diversity of key consonants used in communication (DKCC) to improve understanding of why previously identified value-added predictors are associated with later expressive vocabulary for initially preverbal children with autism spectrum disorder (ASD; n = 87). Intentional…

Eighty-seven preschoolers with autism spectrum disorders who were initially nonverbal (under 6 words in language sample and under 21 parent-reported words said) were assessed at five time points over 16 months. Statistical models that accounted for the intercorrelation among nine theoretically- and empirically-motivated predictors, as well as two…