Recent studies have reported that private schools surpass public schools on numerous educational outcome measures. Analysts have suggested that differences between teachers in public and private schools partly account for the measured success of private schools. This report investigates these differences in terms of teacher time allocation patterns. Specifically, the report asks if public school teachers spend more or less time than private school teachers in classroom teaching, planning and evaluation, extracurricular supervision, or other student-related activities. The report also examines whether differences in teachers' time allocation depend upon demographic, educational, or teaching experience factors, or on school characteristics such as school size or regional location. The study analyzed data from "The Public School Survey of 1984-85" and "The 1985-86 National Survey of Private Schools," using descriptive analysis and multiple regression techniques. The typical full-time teacher spends approximately 50 hours weekly on classroom and nonclassroom school-related activities, with roughly one-half of this time spent in the classroom. The remaining 25 hours are distributed across the other activity categories, with the largest proportion (60 percent) allocated to planning and evaluation activities. For all teachers, there are no significant differences in time usage between public and private school teachers among the activity categories shown. Within each instructional level, some public-private differences do emerge. These and other results are summarized and displayed in numerous tables and appendices. (MLH)