The three stages shown in Figure 1 are intended to demarcate three macro-stages of writing development. Writing skill is shown as continuously improving as a function of practice, as is typical for perceptual-motor and cognitive skills in general. The micro- changes underlying the gradual improvement that drive the transition to the next macro-stage fall beyond the scope of the present article. But, in general, it is assumed that both the basic writing processes of planning, language generation, and reviewing, plus the mental representations that must be generated and held in working memory, undergo continuous developmental changes through maturation and learning within.
