Abstract
The purpose of the present research was to examine the effect on writing of using a hierarchical concept map, which is a kind of diagrammatic external representation, in prewriting. Participants were 96 undergraduate women. The effect of working with an external representation in planning writing was examined by comparing participants who used lists that were sentential external representations and participants who used no prewriting and wrote by a knowledge-telling strategy. Also examined was the effect of causal relations that had been expressed in prewriting which appeared in the written product. The written products of participants who used external representation in prewriting were quantitatively and qualitatively more excellent than those of participants who did no prewriting. When participants who did prewriting were compared, those in the concept map group who used a diagrammatic external representation for their prewriting were able to produce more understandable writing in a shorter time than those in the listing group.
