A variety of sources, including writing samples and videotapes of writing sessions, were examined to determine what speech events underlie the written compositions of students from fourth through twelfth grades. Findings revealed a correlation between different levels of writing competency and four types of speech events: encoding, conversation, presentation, and ritual. Typically, students based their early written work on the simplest form of communication behavior--encoding, which concentrates on processing letters, words, and phrases. Once they had mastered encoding, students began to model their writing on the more complex speech events of conversations and presentations, both establishing a close relationship between the speaker-writer and the reader through conversationally structured writing and creating a greater distance between the two through presentations. The most advanced students used ritual, invoking authority through modeling devices such as footnotes and references. Awareness of the underlying rhetorical situations in student compositions can help teachers develop writing programs sensitive to students' developing abilities. (MM)