Recent developments in such fields as linguistics, logic, information theory, computer science, speech act theory, and psychology can lead to a greater interdisciplinary understanding of the process of writing (defined as purposeful activity involving language use in special modes). Purposes for writing, which may be correlated with the many decisions and selections made in the writing act, are different from those of speech and also differ between various writing modes. An adequate writing model will include explicit strategies for making good decisions. Linguistic research has shown that grammar is related to systems of meaning and language use by the establishment of priorities; sentences typically include both previously known and new material, and information priorities within sentences can be analyzed. To plan whole texts, a writer must be trained in forming hierarchies of topics. The writer can make the message as strong as possible by considering reader backgrounds and expectations and by tailoring his or her approach to logical arrangement accordingly. Explicit knowledge of the decision making processes in writing and of the prospective consequences of those decisions is of key importance in writing well; such knowledge is a great part of good style and correct usage. (A recommended reading list is included.) (DF)