This study focuses on the question of "emotional style," defined as the structure or lack of structure in the interaction between teacher and student. Characteristics of "open" and "structured" teachers and students are defined. It is hypothesized that a matching of teacher and student emotional style will result in greater student achievement. A review of research into teacher-student matching by emotional style is undertaken, and a description of instruments used for data gathering in the present study is given. Phases of the study are defined as: (1) determine the general academic achievement of those upper elementary school students assigned to each of two identified (teacher/open and teacher/structured) classrooms; and (2) compare those students who closely matched the teacher in terms of style to those taught by teachers not matching their own style. Results of phase one indicated that there was no significant difference in achievement between students in a structured and open classroom when the students were nonsystematically assigned to those classrooms and resulted in groups of similar ability and the same average attitude toward structure. Results for phase two did not indicate that matching students with teachers of the same measured style produced higher achievement. It did indicate that students who were classified as open had higher achievement than students who were classified as structured, regardless of the attitude of the teacher as defined by the classroom. It is summarized that the study seems to indicate that in addition to intellectual ability, personality factors, cognitive style factors, and other factors, there seems to be a difference among students in terms of emotional structure or style, since students who were classified as "open" showed superior achievement, regardless of the classroom or the measured style of the teacher, over students who were classified as more structured. Suggestions for further research are discussed. (MJB)