This discourse analysis explored the affordances and constraints of Generous Reading (GR), an alternative writing assessment used in teacher professional development. First, GR is traced through its development in empirical studies. Next, a critical discourse analysis of a GR professional development conversation between three European-American educators is described. A teacher of math and science, a teacher of language arts and social studies and a university researcher discussed an African American girl's math writing. The conversation was excerpted from a larger study of GR. A discourse analysis of this conversation uncovered raciolinguistc ideologies that negatively positioned the student, even as the math teacher began to address new possibilities for instruction. The article concludes with a discussion of culturally sustaining pedagogy used to revise the GR form.