Genre criticism, a method within rhetorical criticism, analyzes texts in terms of their genre: the set of generic expectations, conventions, and constraints that guide their production and interpretation. In rhetoric, the theory of genre provides a means to classify and compare artifacts in terms of their formal, substantive and contextual features. By grouping artifacts with others which have similar formal features or rhetorical exigencies, rhetorical critics can shed light on how authors use or flout conventions for their own purposes. Genre criticism has thus become one of the main methodologies within rhetorical criticism.