INVARIANCE OF RATIO - THE CASE OF CHILDRENS ANTICIPATORY SCHEME FOR CONSTANCY OF TASTE

In this article we study the concept of invariance of ratio through an investigation of children's understanding of constancy of taste-that is, the notion that random samples of a given mixture taste the same-u sing a device that does not resort to conventional symbolism. The pape r begins with a definition of constancy of taste and other quantitativ e analogues. Then it presents a theoretical analysis of how constancy of taste may emerge from the child's additive world and grow into a co nception where taste becomes an intensive quantity. The analysis sugge sts that one's conception of taste constancy is linked in a fundamenta l way to one's conception of invariance of ratio. Following this analy sis, the paper reports a study that demonstrates the absence of taste constancy among sixth-grade children. More specifically, the study sho ws that sixth-grade children base their judgment of the relative stren gth of the taste of two samples from the same mixture on at least one of three (extraneous) variables: the relative volumes of the samples t o be tasted, whether the mixture is thought of as consisting of a sing le ingredient or more than one ingredient, and the relative amount of the ingredients stated in the problem.