Abstract
Given the impact of implementation fidelity on community-based outcomes, it is important to understand how fidelity may change over time as providers learn an intervention. Attachment and Biobehavioral Catch-up is an evidence-based early intervention that assesses fidelity during weekly supervision. Providers are first trained in the infant model, with toddler model training considered to be a separate, specialized opportunity. The current study examined changes in fidelity, measured by "in-the-moment" commenting, as providers moved from infant to toddler certification. An initial drop, with a subsequent increase, in commenting fidelity over the training year was expected. Results were consistent with our hypotheses, demonstrating a main effect of time, with most indices of commenting data initially decreasing and then increasing. These findings are consistent with research suggesting that fluctuation in fidelity is typical within community dissemination and suggests that ongoing supervision after the initial training is useful in facilitating successful skill development.