This paper exemplifies and presents the rationale for notional writing materials which are currently being developed for use with advanced level ESL students. The basic assumption of these materials is that effective writing demands a clear sense of why something is being written, and for whom it is being written. The materials are organized according to the language functions that typically occur within academic papers, such as: focusing, substantiating, recommending and predicting. Within each function, students are presented with a variety of voices and audiences. The main advantage of this approach is that it provides the teacher and the students with a framework in which to judge whether or not the writing is effective in terms of a specific purpose, and appropriate in terms of a specific situation. (Author)