Systems thinking undergirds the mid-course qualitative and quantitative data analyses conducted during a four-year cross-site evaluation of a complex multi-site national research project conducted through the Quality Improvement Center on Early Childhood. Each of four sites has a unique intervention designed to build protective factors that prevent maltreatment of young children. The interventions affect the individual, relationship, community, and societal domains of the social ecology. Each domain functions as a subsystem of a broader system. The mid-course analyses deepen our understanding of patterns, paradigms, and system dynamics. This deeper understanding, in turn, help us rethink our remaining data collection, analyses, interpretations, stakeholder involvement, and dissemination of findings and methodological learning. We describe the purposes, tools, processes, benefits, challenges, and cautions of using a systems orientation in the mid-course analyses. This is the Powerpoint presentation for AEA 2012 conference session 665 with the title listed above. The presentation is by Patricia Jessup, Marah Moore, and Beverly Parsons. #Cluster,Multi-SiteandMulti-LevelEval #HumanServicesEvaluation #2012Conference #SystemsinEvaluation #MixedMethodsEvaluation #ProgramTheoryandTheoryDrivenEvaluation