AbstractThe current study conducted a comparative analysis of the effects of select components of Parent–Child Interaction Therapy, labeled praise, behavior descriptions, and reflections on child vocalizations in two children with autism spectrum disorder and accompanying language delays using a concurrent multiple baseline across participants design. The frequency of verbalizations, the frequency of different verbalizations, and the mean length of utterance of words (MLUw) were measured during a baseline condition followed sequentially by two experimental conditions during a free play environment. The total number of therapist–child interactions remained consistent across all experimental conditions such that only the topography of the interactions varied across conditions. During the first experimental condition the clinician used labeled praise and behavior descriptions during child play. After establishing stability of changes under these conditions, the therapist systematically added reflections of child vocalizations in the second experimental condition. Total verbalizations, different verbalizations, and MLUw increased following the introduction of labeled praise and behavior descriptions. Total verbalizations and different verbalizations increased and the frequencies accelerated following the systematic introduction of reflections. The study showed the relative value of reflections of child verbalizations as a powerful component of Parent–Child Interaction Therapy procedures to facilitate verbalizations by children with autism.