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 situational perception of a subject cannot be divorced from a subject's active reconstruction of past experiences nor separated from cyclic phenomena and external regularities. Obligatory and optional features of a task a subject performs are viewed as a function of the immediate contextual situation. Examples center on the developmental processes of a child. (BJG)