The major purpose of the study was to examine what constitutes effective teaching as defined by measured increases in student learning with a focus on the instructional behaviors and practices. Ordinary least squares (OLS) regression analyses and hierarchical linear modeling (HLM) were used to identify teacher effectiveness levels while controlling for student-level and class/school-level variables. Actual achievement of 1936 third grade students in 85 classrooms on the Virginia Standards of Learning (SOL) Assessment results in English, Mathematics, Social Studies, and Science were compared to expected achievement resulting in an indicator of teacher effectiveness. Based on student learning gains, teachers were divided into quartiles. The statistical modeling approach facilitated comparisons of outcomes that were free of influences of identified extraneous variables. A double blind design was selected for in-depth cross-case studies with teachers from the highest quartile representing highly effective teachers (N = 5) and the lowest quartile the less effective teachers (N = 6). The observation team assessed the third grade teachers (N = 11) based 20 categories within four domains: instruction, student assessment, classroom management, and personal qualities. Key findings indicate that effective teachers scored higher across the four domains. Additionally, effective teachers tended to ask a greater number of higher level (e.g., analysis) questions and had fewer incidences of off-task behavior than ineffective teachers. The exploratory study identified instructional behaviors and practices of teachers that result in higher student learning gains.