An analysis of the quantitative processes underlying conservation of quantity is presented. Models of three quantitative operators--subitizing, counting, and estimation--are derived from adult performance in quantification tasks, and some features of the operators are described. The emergence of conservation is described in terms of the…

Elusive developmental processes are most often examined in the context of the philosophic problem of scientific determinism. The Markov process model, enhancing a probabilistic viewpoint for the explanation of developmental data, should be restricted. Attention should be focused on the immediate context and situational setting of a subject. The…