Data from a growing number of research studies indicate that children with hearing loss are delayed in Theory of Mind (ToM) development when compared to their typically developing, hearing peers. While other researchers have studied the developmental trajectories of ToM in school-age students who are deaf and hard of hearing (DHH), a limited number have addressed the need for interventions for this population. The present study extends the current research on ToM interventions to the PreKindergarten and Kindergarten levels. This study used a single-case multiple-baseline multiple-probe across skills design with replications across classrooms to examine the effects of a ToM intervention on participants’ false belief understanding as well as outcomes on a near generalization measure (i.e., Sally-Anne Task, Baron-Cohen, Firth, Leslie, 1985) and a far generalization measure (i.e., five-task ToM developmental scale, Wellman & Liu, 2004). A thought bubble intervention (i.e., a visual representation of what people are thinking) developed by Wellman and Peterson (2013) was modified in key areas: (a) participants were substantially younger than the population in the original study and thus required a pre-teaching phase addressing vocabulary and materials, (b) manipulable materials were created from the description provided in the Wellman and Peterson (2013) study along with parallel materials used in assessment probes, (c) a certified teacher of DHH children provided direct instruction to participants in a small group setting, (d) study length was increased to 25 weeks, and (e) methodological design change (i.e., group design to single-case design). These modifications addressed the need for evidence-based ToM interventions that are both proactive and easily implemented by teachers in a classroom setting. Results from the single-case design portion of the study indicate a functional relation between the thought bubble intervention and the participants’ acquisition of the targeted skills in each stage, although progress was not uniform. Results from the pre-post assessments indicate that the children did make progress up the scale, however, children who used spoken language tended to proceed faster through the stages than those who used sign language. These results inform the field in regard to the efficacy and feasibility of a ToM intervention for young DHH children
