The study was conducted to gain an understanding of pupil-interaction and pupil-movement in an open-area learning environment. The only measures that were available were not sufficiently suitable and it was necessary to construct a new instrument to gain a valid measure of pupil behavior in a classroom setting. As a result, the Interaction-Network instrument was developed. Three elementary schools were used in the study. Two of the schools contained open-area classrooms and these constituted the experimental schools. The third school, which acted as the 'control' situation, employed a more traditional form of classroom instruction. Pupils from Grades 5, 6, and 7 participated. Samples of approximately 20% of the pupils in each grade at all three schools were observed. A descriptive analysis showed that there were major differences in both pupil-interaction and pupil-movement between the experimental schools and the control school. The role of the teacher was more pronounced in the traditional type school while in the open-area schools there was much more pupil-movement and pupil-interaction. Recommendations were made for the use of the instrument in future research. (Author)