The purpose of this study was to determine if educators and prospective teachers were equally knowledgeable regarding the following three recommended principles and practices for developing oral language skills of first grade disadvantaged students: (1) Teachers should encourage children to express themselves freely and have the children do most of the talking. (2) Teachers should employ questions which permit and encourage the children to use their language for thinking. (3) The teacher should accept the language of the children. The study also attempted to determine whether role and prior training were reflected in the knowledge of the subjects. In order to ascertain this, the following groups were asked to evaluate 12 classroom verbal interactions in printed form: supervisors of primary teachers, first-grade classroom teachers of disadvantaged students, teacher trainees who had completed a language course, and a comparison group which had no language training. Supervisors scored higher than each of the other groups in selecting the recommended principles and practices. The classroom teachers and teacher trainees were virtually equal, both being slightly superior to the comparison group. This study indicates the inadequacy of present in-service and pre-service programs in the development of oral language for the disadvantaged student. (Author/DB)