A cognitive approach to the interrelation of writing and reading assumes that production and comprehension of written text depend upon cognitive and affective schemata used in concert by a writer or reader to produce or encode, store, and retrieve text information. Both comprehending and composing are basic, complex, interactive processes with students varying in their ability to focus on getting or producing "straight" messages and predicting what messages or responses ought to be. In addition, both composition and comprehension involve prototypical knowledge of the subject matter and the structure or format of texts, the content schemata. Also involved is prototypical knowledge about processing factors--the procedures for composing and comprehending an extended definition or summary, for instance, which are called process schemata. Content and process schemata change in response to the demands of a situation and become more elaborate and specific with experience. A cognitive approach stresses the role of the teacher in helping students develop these structures, through direct instruction, experiences with reading and writing, and exposure to a variety of reading and writing tasks. With a cognitive approach to writing and reading relationships, it seems that composition and comprehension are very much alike: both use schemata for subject matter, micro and macro structure, and procedures. The sooner students become expert writers and readers, the sooner they can role play and become even more expert, with writers becoming reader-based and readers becoming writer-based. (HOD)