A research program to investigate interactions of instruction styles and learner characteristics related to learning results in junior high schools is described. Data was gathered both by observation of the teacher in the classroom and by responses of pupils on their perceptions of the teacher. Different teaching styles are defined and referred to as functional teaching styles, because they deal with the functioning of the teacher in the teaching-learning situation. There are four phases to this research project: (1) determination of the teaching styles of about 100 junior high school teachers; (2) determining the pupil characteristics that are related to teaching styles; (3) determination of the criteria to which the interacting of teaching styles and pupil characteristics were compared, and (4) in the future, conducting the interaction project with a new group of teachers and pupils. The research is incomplete at this time, and only one hypothesis emerges as having strong support--in class settings a teacher who teaches by means of questions and giving feedback rather than by means of explaining and answering is more effective than average when the criterion is a cognitive one. (JD)