This paper reports the findings of a case study that explores the relationship between feedback and revision in the online teaching of two EFL adult writers. The model of feedback adopted was one of content-based feedback followed by form-focused feedback in a series of multidraft compositions. A quantitative analysis of minimal terminal units (t-units) (Hunt, 1965) was used to analyze the relationship of feedback and revision following the two types of feedback. A paired t test showed content-based feedback to yield significantly more revisions than form-focused feedback, (p less than 0.001). To obtain a measure of the amount of information conveyed per draft, information units or "i-units" were then defined (see Savignon, 1972). Drafts subsequent to content-based feedback showed a greater increase in i-units than did those following form-focused feedback, (p less than 0.05). Discourse analysis was then conducted to examine the negotiation of meaning that took place between feedback and revision. Content-based feedback was analyzed with particular attention to a type of commentary known as "question-form comments." Question-form feedback was seen to prompt direct responses from both learners. Implications of these findings are drawn for the role of teacher feedback, both in computer-mediated and more traditional teaching contexts of second-language writing. (Contains 5 tables.)