Scholars such as Diane Kelly-Riley and Patricia Bizzell have argued that the student writing feature most likely to place a student into a basic writing course is the presence of dialect other than standard academic English. This essay examines how assessment practices can foster students' diverse languages rather than inhibit them. I conducted a semester-long participant observation of two sections of first-year writing at Midwestern University, also considered basic writing preparatory courses, in order to examine how instructors assess varieties of English. One of these sections exclusively enrolled nonnative speakers of English; the other section enrolled both native and nonnative speakers. A key finding is that students modeled the vocabulary they used to discuss their writing and the writing of their peers to match the assessment language used by the program. Composition scholarship recognizes that language difference and variation is intrinsic to all language, thus, programs should take care to consider issues of language diversity when designing rubrics or other assessment tools to avoid unfairly penalizing students. I discuss one possible model for increased attention to language diversity in assessment.