The focus of this ongoing research is the effectiveness of coaching in improving the quality of teacher-child instructional interactions in Head Start classrooms. This study examines the relationship between two measures: Classroom Assessment Scoring System (CLASS) and a Project Approach Fidelity form developed by the authors. Linear regressions were used to investigate predictors of CLASS domain scores. The Project Approach Fidelity scores have positive predictive relationships to the CLASS domains. Higher Project Approach Fidelity scores predicted higher scores for the CLASS Emotional Support, Classroom Organization, and Instructional Support domains. Consistent with their findings, the authors recommend that use of the Project Approach be combined with attention to behaviors emphasized in the CLASS to help teachers intentionally improve instructional quality in prekindergarten classrooms. (author abstract)