This study examines the revision histories of 10 Wikipedia articles nominated for the site's Featured Article Class (FAC), its highest quality rating, 5 of which achieved FAC and 5 of which did not. The revisions to each article were coded, and the coding results were combined with a descriptive analysis of two representative articles in order to determine revision patterns. All articles in both groups showed a higher percentage of additions of new material compared to deletions and revisions that rearranged the text. Although the FAC articles had roughly equal numbers of content and surface revisions, the non-FAC articles had fewer surface revisions and were dominated by content revisions. Although the unique features of the Wikipedia environment inhibit strict comparisons between these results and those of earlier revision studies, these results suggest revision in this environment places unique structural demands on writers, possibly leading to unique revision patterns. (Contains 3 figures, 4 tables and 4 notes.)