Investigated developmental changes in object-sorting responses of 60 3-, 4-, and 5-yr-old preschool children in terms of 3 systems of measurement incomplete conceptual transactions, conceptual areas, and culturally reinforced concepts. It was demonstrated that almost every measure within these systems provided evidence of gradual, continuous development of conceptual behavior across these age groups. It is concluded that these dimensional forms of analysis provide higher predictive efficiency and more precise denotative meaning than corresponding forms of analyses based upon the assumption of typological, qualitatively distinct levels of developmental change, such as Goldsteins abstract-concrete formulation of the developmental stages of magic-wand perseveration, confabulation, and confabulatory combination proposed by Klopfer, Spiegelman, and Fox. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.