Teachers often act more like artists, in the sense that they tend to jump back and forth between new trends in pedagogy and theory. Meanwhile, the public, concerned that student evaluation as manifested in grading procedures rests on shaky ground, are losing faith in the credibility of their children's teachers. One way for teachers of all subjects to establish credibility in student evaluation is to rest grading practice on the "Cooperative Principle" theory of H. P. Grice. Grice lists four maxims for his principle as it relates to conversation: quantity, quality, relation and manner. Grice's analysis of speech and ordinary conversation can be easily adapted for use in grading student's written assignments. The maxims are internally recognized by members of a culture as essential to successful communication, and writing can be clearly judged and critiqued according to Grice's model. Early in a semester, the teacher should introduce the students to Grice's concepts, so that they begin by knowing how their writing will be evaluated. These principles can also be easily transposed across the curriculum into other academic fields. In short, teachers concerned with writing can easily utilize Grice's model as a means of exploiting what they already know and internally understand about everyday conversation. (HB)