The conceptual foundation and initial psychometric evidence are provided for the "Instructional Coaching Rating Scales" and "Interaction Style Scales--Teacher Forms." These forms are part of a multicomponent online assessment system designed to evaluate the effectiveness of coaching skills and interactions that support the needs of teachers and students. Specifically, the article presents the theory, evidence, and measurement framework for the system. Findings indicate that the "Rating Scales" and Interaction Style Scales--Teacher Forms have very good internal structures based on multiple fit statistics for confirmatory factor analyses, high internal consistency, good item-to-scale total correlations, and freedom from item bias. Collectively, this promising statistical evidence is supportive of valid score inferences. Study limitations and directions for research are discussed.