This study investigated the relationship between children's ability to conserve on Piagetian tasks and six measures of the openness of classrooms which comprise the Dimensions of Schooling Questionnaire (DISC): (1) individualization of instruction; (2) student independence; (3) environmental flexibility; (4) nongradedness; (5) flexibility of student evaluation; and (6) flexibility of curricular materials. Teachers of kindergarten, first, second, and mixed grades responded to the questionnaire. The Piagetian tasks were administered to a random sample of three children from each classroom. Three types of conservation tasks were used: substance, length, and number. The correlation between the DISC factor nongradeness was significant. The positive correlation between the nongraded factor and the children's scores on the conservation tasks indicated that the existence of such nongraded instructional patterns is related to better performance on the reasoning tasks used in this study. None of the other correlations between the major variables were found to be significant. (Author/JD)