THIS STUDY INVESTIGATES THE EFFECT OF A TEACHER'S BELIEF OR CONCEPTUAL SYSTEM ON HIS TEACHING METHOD AND ON THE CLASSROOM ATMOSPHERE CREATED BY THAT TEACHING METHOD. A BELIEF SYSTEM WAS CHARACTERIZED AS EITHER CONCRETE OR ABSTRACT. A CONCRETE SYSTEM WAS REPRESENTED BY A TENDENCY FOR THE TEACHER'S INSTRUCTIONAL APPROACH TO BE MORE STRUCTURED, MORE INVARIANT, AND LESS FLEXIBLE THAN THE APPROACH OF A TEACHER MANIFESTING AN ABSTRACT SYSTEM. TEACHERS WERE GIVEN THE "THIS I BELIEVE" TEST (TIB) AND THE "CONCEPTUAL SYSTEMS TEST" (CST) TO INDICATE WHICH BELIEF SYSTEM THEY WOULD BE PLACED INTO, NAMELY, (1) CONCRETENESS-ORIENTED, (2) ABSTRACTNESS-ORIENTED, AND (3) IN-BETWEEN. TEN TEACHERS WERE SELECTED FOR EACH CATEGORY. THESE 30 FEMALE HEAD START TEACHERS WERE OBSERVED WHILE CONDUCTING THEIR CLASSES OF PRESCHOOL CHILDREN AND WERE RATED ON A 26 DIMENSION CHART. EACH DIMENSION REPRESENTED EITHER A DESIRABLE OR AN UNDESIRABLE TEACHER TRAIT. IT WAS HYPOTHESIZED THAT TEACHERS IN CATEGORY (1), CONCRETENESS-ORIENTED, WOULD SCORE LOWEST ON DESIRABLE TRAITS AND HIGHEST ON UNDESIRABLE TRAITS, THAT ABSTRACTNESS-ORIENTED TEACHERS WOULD SCORE HIGHEST ON DESIRABLE TRAITS AND LOWEST ON UNDESIRABLE TRAITS, AND THAT THE IN-BETWEEN GROUP WOULD SCORE IN THE MIDDLE. THE RESULTS SUBSTANTIALLY SUPPORTED THIS HYPOTHESIS. (WD)