LAUSR

In the present study, we provide a preliminary evaluation of the validity and reliability of using weighting procedures to measure communication in play samples for preschool‐aged boys with autism or fragile X syndrome (FXS). Because weighting procedure communication scores (WPCSs) reflect growth in both communicative frequency and complexity, establishing the psychometrics of the component scores, in addition to the overall metric, affords investigators the opportunity to describe growth within and across skills. Results, for both groups, provide support regarding the psychometric appropriateness (i.e., convergent validity, divergent validity, and internal consistency) for all WPCSs. That said, a trend was observed for reliability scores to be slightly lower or more variable in boys with autism than in boys with FXS. Finally, although significant associations were observed in the associations between WPCSs across play contexts, contexts effects were observed for all three WPCSs. Together, results from this study provide promising preliminary data indicating the utility of using WPCSs in children with neurodevelopmental disabilities.