The long-term objective of this work is to examine the impacts of planned variations of theory- informed behavioral supports provided to caregivers; caregivers receive these supports when implementing an empirically validated 15-week early-literacy intervention with their children with language impairment (LI). An empirically validated intervention for improving the early-literacy skills of children with LI, and potentially reducing risk for future reading disability, is Sit Together and Read (STAR); STAR features repeated reading of storybooks in which adults embed explicit references to print-related targets. When implemented by children's caregivers, children with LI show significant improvements in their early-literacy skills, which may in turn boost future reading performance. However, recent studies show that caregiver implementation of two 'active ingredients' of the intervention which are necessary for it to be delivered at the desired strength- intensity and dosage - is low for a substantial subset of caregivers. By applying a four-step approach to developing theory-informed behavior change interventions, the proposed study examines how four behavior-change techniques (referred to as Reward, Feedback, Motivate, and Encourage), delivered in isolation and in multiple combinations, may influence caregivers' implementation of the intervention with respect to intensity and dosage and, in turn, children's outcomes. To address these goals, the study will involve 128 caregivers and their 4- and 5-year- old children with LI, each assigned to one of16 different conditions within a factorial experiment. The factorial design allows us sufficient power to detect medium-sized effects and to test specific behavior-change techniques on their own and in multiple combinations. Caregivers will implement the 15-week STAR intervention at a planned intensity of 60 sessions (within-session dosage of about 6-8 explicit print references). Study results will determine whether caregivers' implementation can be enhanced via exposure to theoretically based behavior change techniques.