Abstract:
Little is known concerning the onset of the stage of formal operations and the progress .of the acquisition of the component skills of that stage. Nine hundred students were tested on a written test of formal operations and an ordering-theory approach was used to determine the order in which the sixteen key operations of the stage are arranged and the relationships between them. Two hierarchies were discovered and the significance of these struc- tures for Piagetian theory and adolescent education are discussed.