Previous research indicates that the Child Observation in Preschool (COP) and Teacher Observation in Preschool (TOP), a companion set of observational tools used to assess the quality of preschool classrooms, capture important aspects of the preschool environment that are associated with children's growth (Farran et al., 2017; Nesbitt et al., 2015; Spivak & Farran, 2016). This study is the first to assess the convergent and predictive validity of these tools in community-based child care centers and compare the tools to the Classroom Assessment Scoring System Pre-K (CLASS Pre-K), a widely used classroom observation tool. We collected COP-TOP and CLASS Pre-K data in 138 classrooms in Georgia as part of a validation study of Georgia's Quality Rated and Improvement System. We also collected child assessment data from 583 preschool-aged children in those same classrooms. Over half of the COP-TOP classroom processes were moderately correlated with at least one of the three CLASS Pre-K domains. COP-TOP classroom processes related to time spent in transition, time spent engaging in sequential activities, involvement in learning activities, and opportunities for math learning were associated with children's math skills, preliteracy skills, and socioemotional development at the end of the year, after controlling for their scores at the start of the year and demographic characteristics. All three CLASS Pre-K domains were significantly associated with children's socioemotional development. We discuss the implications of these results for assessing quality in early care and education programs. (author abstract)