This study examined whether the incidence of classroom behavior problems of students with behavior disorders were reduced in collaborative/cooperative classes when compared with traditional special education classes. Subjects were 15 students in grades 6 through 8 who spent half their class day in a collaborative/cooperative classroom and the other half in a traditional classroom. In the collaborative/cooperative model, a regular education teacher and a special education teacher worked together in a classroom with both regular and special needs students. The number of behavior problem referrals to the school office was compared for each of these settings. Results indicated a significant difference in number of office referrals, with 31 percent of subject referrals coming from the collaborative/cooperative classes and 69 percent from special education classes. Three factors of the collaborative/cooperative setting are suggested as responsible for this difference: (1) peer pressure; (2) clearly defined roles for the collaborating teachers; and (3) a strong discipline plan. (Contains 13 references.) (DB)