This analysis of 83 scoring rubrics and grade definitions from writing programs at U.S. public research universities captures the current state of the struggle to define and measure specific writing traits, and it enables an induction of the underlying theoretical construct of "academic writing" present at these writing programs. Findings suggest that writing specialists have managed to permeate U.S. first-year writing assessment with certain progressive assumptions about writing and writing instruction, but they also indicate critical areas for revision, given such documents' critical gatekeeping role at postsecondary institutions. The study also raises a broader question about the difficulties of rhetorically constructing "writing ability" in a way that is consistent with the contextualist paradigm dominant in contemporary writing studies. (Contains 8 tables, 4 figures and 9 notes.)