anner in the classroom. Educators who prefer to have children learn to make a scientific interpretation rather than a mythological interpretation of natural phenomena, and one way to introduce scientific interpretations is to analyze any change as evidence of interaction. One way in which this teaching device can function is if there is an instructional period of several class sessions in which the students are engaged in "play" with new of familiar materials; followed by is a suggestion of a way to think about observations; lastly there is a further extermination in which the students can explore the consequences of using their discoveries . Through the process of guided discovery, the student goes from observation at the beginning to interpretations at the end (Athey & Rubadeau, 1970, p. 245). In Piaget's study of the operations that underlie the system of scientific concepts related to number, measurement, physical quantities, and logical classes and relations, structural models were needed to explain the processes involved in the formation of these concepts (Inhelder & Sinclair, 1974, p. 23). The grouping of classes and relations describe the characteristics of the end product of process of growth as a particular system of mental operations. The logical and infralogical systems of concrete thought prolong the action structures of the sensorimotor period, but because they are subsytems of extensive higher-order structure, they pave the way for the mathematical group structures of the period of formal thought. Piaget proposes ( Piaget & Inhelder, 1971, p. 387) that knowing the object means acting upon it in order to transform it and discover ...
