Focusing on purpose in the writing of college freshmen, a study examined the writing processes and how they related to the conceptions of purpose of four freshmen enrolled in a composition course at Indiana University. Discourse-based interviews were conducted before and after the students completed three tasks designed to vary their choice of audience, mode, and focus. Analysis revealed two tendencies that characterized how students viewed the purpose for their writing. Some students were "rhetorically limited" in the development of their purposes and proceeded according to a performance oriented, dualistic, mechanistic view of writing. Others were "rhetorically flexible," constantly moving between their global and operational purposes. Results indicated that students' models of writing and literacy probably influenced their writing more than the specific features of the tasks to which they were responding. At the highest level, these models either inhibited or enhanced the students' thinking processes by restricting or opening up possibilities for more specific purposes within and beyond the texts they were producing. Results support a writing pedagogy in which a qualitative reformulation of students' discourse models is more central to their continued learning than the quantitative acquisition or mastery of certain discourse-specific skills. (An analysis of one subject's response patterns and a three-page reference list are included.) (JD)