THE RELIABILITY OF OBSERVATIONS OF TEACHERS' CLASSROOM BEHAVIOR.

The Teacher Practices Observation Record (TPOR) is an instrument for measuring classroom behavior by systematic observation. It attempts to measure the agree ment-disagreement of teachers' observed classroom behavior with educational prac tices advocated by John Dewey in his philosophy of experimentalism. In addition to presenting this in strument and briefly describing its development, the authors will report the reliability data obtained by using it in a study of observations of filmed teaching episodes. The data reported on the TPOR will be placed in the context of the general problem of study ing reliability, and will be used to demonstrate a new design for estimating the reliability of such observational measurements.