This instrument for describing writing is designed for use by teachers and researchers at the secondary and college levels. The two main sections are an outline of the complete instrument and the instrument itself. Various categories of the instrument can be used to describe general, descriptive, and explanatory prose; other categories are related to the writing process, writing behavior, and the written product. For most categories, examples are given and the author is cited. The instrument is designed to be self-contained and explicit, but it is presumed that its users have some knowledge of the measurement of writing ability, of the composing process, and of key works such as those by Walker Gibson, Francis Christensen, Janet Emig, Kellogg Hunt, and Frank O'Hare. (Author/AA)