This article examines the translatability of Kane's (1992, 2006, 2013, 2016) argument-based validation approach to the aims and needs of college writing assessment, particularly given (a) the elusive ways in which writing is theorized in the post-process era, and (b) the composition/writing assessment community's concern for matters of social justice. As part of this process, I review current conceptualizations of writing in the composition literature; I then discuss some overarching implications of assessment as a decision-making process; and then I review the underlying principles of Kane's approach. From there, I discuss which elements of Kane's theory apply more to testing and test development and less to writing assessment as theorized and practiced today; and then I offer criticism of Kane's theory and call for adaptations that could be made to help forge a theory of assessment validity more suited to the goals of writing assessment and composition studies at large.