This paper argues that unsatisfactory argumentative and expository texts generated by college students represent a simplification of complex discourse structures. It asserts that the usual explanations for poor student performance, such as illogical thinking, lack of academic commitment, and poor mastery of grammar, are unsatisfactory. The paper proposes that inadequate writing stems from a simplified script in the inexperienced student writer's internal representation of what argumentative discourse should be. The simplified script lacks some features that mark successful academic writing because students are unaware of the cognitive executive routines underlying sophisticated argument. When students learn to execute rhetorical strategies of decision-making, their simplified mental representation of academic discourse will give way to a mature sophisticated script, then their writing will become convincingly substantiated, more coherent, and better focused. (MDM)