This study was designed to investigate the relationship between wait-time and two classroom interaction variables: cognitive level of teacher questions and length of student response. The interval of time between a teacher question and the next verbal response by teacher or student (wait-time) was measured using an electrocardiograph with calibrated paper connected to an audiotape recorder. Students taught to categorize and graph their own questioning behavior increased the rate at which they asked high-level questions. The wait-time for experimental subjects increased and was directly related to the length of student response. Control subjects did not show these changes. (Author)