A study examined the influence of prior knowledge on the quality of responses in three process-approach tasks: writing, conferencing, and revising. Subjects, 20 high-knowledge and 20 low-knowledge fourth grade students, wrote stories about a baseball game. Propositional text bases of first and second drafts were analyzed according to six categories of baseball grammar (setting, state, action, auxiliary action, nongame relevant action, and nongame irrelevant action). Comments about baseball content made during peer conferences were coded using the same six categories. Differences in the content of first drafts, conference comments, and second drafts were found to be related to prior knowledge. Results tended to support the instructional recommendations of composition researchers that topics process-approach writing lessons be selected according to students' prior knowledge. (Author/HTH)