The objective for the Writing Skills II [part of a three-course sequence] students is to write grammatically correct essays with unity, support, and coherence. These students start at the paragraph level with a focus on topic sentences, supporting evidence, and grammar, and are given ample classroom time for revising and editing with teacher input. [...] The majority of my students were ready to move on to a five-paragraph essay. I added in some reading-based assignments, but allowed students to continue to use their personal experiences as supporting evidence. On the other hand, WS III students start off with the five-paragraph essay, usually experience-based as well. They concentrate on writing thesis statements, grammar, and eventually work up to doing peer editing in class. They also move on to reading-based essays and using citations by the end of the semester. The objective for these students is, in addition to proper grammar, unity, support and coherence, to be able to edit their own papers, and to start to critically read an article and write about it objectively.
Three obvious values/assumptions grounding this rationale for teaching the five-paragraph essay are clarity=good, becoming "grammatically correct" is somehow tied to arresting form and rendering it a-rhetorical, and a notion of writing acquisition as progress. I call these "value/assumptions," I guess, because they seem so grounded in values as to be impervious to debate.