Reported is a study of teacher-pupil and pupil-pupil interactional differences between a traditional instruction method and an inquiry-centered learning method for 18 science classes at the fourth and fifth grade levels. Nine classes were assigned to the experimental group, and the remaining nine classes received a traditional program. Classroom activities were observed and recorded for evaluation. Analyses showed that the traditional method had significantly more teacher-pupil verbal interaction than did the inquiry-centered method. No significant differences was found in pupil-pupil interactions between the two groups, but boy-girl interaction was significantly higher within the experimental group. More interaction was exchanged between teacher-boy or boy-teacher than between girl-teacher and teacher-girl. (Author/CC)