The goal of this study was to analyze the development of the relationship between conceptual and linguistic processes as regards idea ordering and structuring (linearizing), when composing a text. Participants (from 7th graders to University students) were required to compose a text using a list of eleven scrambled ideas. Conceptual rules allow to a priori determine an optimal ordering of these ideas. Results showed a significant increase, with grade level, in the establishment of the postulated conceptual order, and in the linguistic elaboration of the text structure. A large autonomy was observed between conceptual and linguistic processes. The discussion considers the following points: The relevance of the notion of text optimal order; the unequal development with grade level of the varied linguistic skills; the dissymmetry in conceptual-linguistic relationships; the usefulness of the experimental paradigm; some consequences for education. (Contains 5 tables and 3 figures.)