This study investigated whether differences exist between classrooms of expert and novice teachers on the cohesion, communication, and flexibility dimensions of the "Classroom Systems Observation Scale" (CSOS). Principals identified 10 expert and 10 novice elementary school teachers from 8 public and private schools. A 50-minute classroom observation using the CSOS was conducted for each classroom. Results showed that expert teachers' classrooms had a significantly higher level of flexibility within the balanced range of functioning than did novice teachers' classrooms. No differences between expert and novice teachers' classrooms were found on the cohesion and communication dimensions. These findings support prior research on expert-novice teacher differences. School psychologists can use this knowledge to help new teachers develop a more balanced, flexible classroom, thus improving the classroom system. (Contains 23 references.) (Author)