A study analyzed argumentative essays written to both friendly and hostile audiences by 12 high school seniors, 24 college freshmen, and 16 college juniors and seniors. The high school students were randomly selected from college-bound English classes that had stressed reading and writing about literature but had also included some work in expository writing. Writing samples were gathered near the end of the academic year, and thus the high school students' writing abilities were largely those they would carry into college. College students were selected from various disciplines and class levels. All subjects wrote argumentative papers on two separate occasions, one paper for a "friendly" audience and one for a "hostile" audience. After holistic rating, the papers were analyzed for degree and kind of audience activity and for the writer's level of intellectual development. Hostile-audience papers were also coded for their rhetorical bases of justification of argument. Results showed that level of intellectual development was a more significant predictor of holistic scores than demographic variables. Significant relationships between writers' audience activity, holistic scores, and levels of intellectual development were found. Four hostile-audience variables--audience strategy and response and the dogmatic and logical bases of argument--predicted significantly for scores and yielded similar results to those obtained when level of intellectual development was considered in the regression. The hostile audience papers evoked the most audience activity, both positive and negative, especially dialectical activity. (Nine pages of references as well as statistical tables and figures are provided. The appendixes consist of student instructions for the two writing assignments and an audience coding scheme.) (FL)