Studies that use a single-case design (SCD) measure outcomes for cases (such as a child or family) repeatedly during multiple phases of a study to determine the success of an intervention. The number of phases in the study will depend on the research questions, intervention, and outcome(s) of interest (see Types of SCDs on page 4 for examples). For the Home Visiting Evidence of Effectiveness (HomVEE) review, the interventions of interest are early childhood home visiting models, and outcomes of interest must fall within at least one of eight domains. (author abstract)