Abstract: Objectives: The child-caregiver relationship is the foundation for which intervention occurs. Therefore, the acceptability of the intervention should be considered for both parties. Indices of happiness (IOH) have shown to be effective in assessing social validity and providing insight to improving interventions to promote better quality of life. However, to date, there is limited attention to the integration of IOH in very early caregiver-led intervention. The purpose of this study is to explore how researchers and clinicians might collect direct data on IOH to assess the acceptability of an intervention. Methods: Participants in this study included 4 children, ages 19–26 months old, identified as “at-risk” for autism, and their caregivers. Caregiver-led intervention focused on pairing, play, and following the child’s lead. IOH data was collected on both child and caregiver using 10 s partial-interval recording. Data analysis from the intervention is presented using three different approaches: pre/post-analysis on an individual level, pre/post-analysis on a dyad level, and during intervention as a primary dependent variable. Results: Variations were seen in levels of happiness, both on an individual level and dyad level. IOH for caregivers increased in relation as their fidelity increased but child IOH decreased as they acquired the targeted skill. Conclusions: Direct observation of happiness data is likely to provide valuable insight into participants perception of an intervention. And retrospective analysis may be a valuable tool for reflection and guidance and planning of future interventions
