30-line abstract The epidemic of child abuse in the U.S. (>675,000 confirmed annually) causes massive harm to children and the adults they become. Sequellae include physical disabilities and neurological damage, mental health problems, maladaptive behaviors, and perpetuating cycles of abuse. Young children (aged 0–5 years) are particularly vulnerable to victimization. They account for >75% of deaths from abuse and a greater proportion of victims than older children for all categories of maltreatment except sexual abuse. Yet despite 8-12 million American children being in childcare, early childhood professionals (ECPs) report fewer than 1% (~2,500) of all substantiated cases of child abuse. Research shows that ECPs are not adequately prepared to identify at-risk children, and there is a wide-spread need for interventions with demonstrated efficacy for improving ECP reporting of suspected child abuse. That said, efforts to raise ECP reporting rates must be careful not to promote inappropriate reporting, which wastes scarce resources and causes families undue stress. Our parent 5-year study is evaluating the efficacy of an innovative educational intervention, iLook Out for Child Abuse (iLookOut) at promoting and sustaining both knowledge, and behavior change with regard to concerns about child abuse. Grounded in an experiential learning conceptual model, iLookOut is a multi-media, online intervention that engages learners emotionally and cognitively using an interactive, video-based storyline that provides education, challenges learners with decision-points, and gives critical feedback. iLookOut uses gamification strategies to promote experiential learning through simulation, problem-solving, and practice opportunities to apply new information and understanding. It also includes follow-up activities to promote retention and integration of new knowledge, and help ECPs remain aware and engaged. Prior studies demonstrate that iLookOut's Core Training significantly improves knowledge and attitudes about reporting suspected child abuse, and is well received by ECPs. To evaluate its impact on sustaining knowledge and changing behavior, the parent grant will administer knowledge and behavioral measures before and after iLookOut's Core Training and its Advanced Training. For the Head Start version of Core Training, the parent grant will deploy and evaluate an English-language version, while this supplement will create, deploy, and evaluate a Spanish-language version. Subsequent analysis will analyze for any outcomes-based differences between ECPs who complete the English- versus Spanish-language version. Additionally, we will create and deploy a brief (30-60 minute) pilot, micro-learning course to help learners better appreciate how cultural diversity, implicit bias, and disproportionality relate to child abuse and its reporting. The primary goal of this supplement is to increase access to, and usability of, iLookOut's Core Training while also examining its...