Writing is an act of self construction. Considering how students process information can improve the quality of instruction in composing courses, but only if quantifiable, verified models of cognitive functions are taken to heart and applied to teaching methods in the classroom. C. G. Jung's model of the four functions (thinking, sensation, intuition, and feeling), and the Myers-Briggs Type Indicator (developed to discern preferences of cognitive style of thought) are useful for two reasons: (1) the model's empowering and self-orienting descriptions of cognitive functions is richer and more complex than other cognitive functions models, and (2) the model offers a useful guide in helping students understand their writing problems in the classroom. The four functions model predicts that people will show a significant preference for certain kinds of information processing; will be predisposed to compose using certain well-developed skills and to ignore others; and will usually have predictable writing habits, both good and bad, that can be penetrated by using the Cognitive Functions Model to group and work with individual students. This model also works well in cross-cultural classrooms, since it is a westernized version of a universal metaphor for seeking "wholeness." (A model of the four functions and 27 references are attached.) (MM)