WEBPutting DOK into Practice with Hess’ Cognitive Rigor Matrix. Dr. Karin Hess combined Bloom’s taxonomy and Webb’s Depth of Knowledge into a single chart which she calls a Cognitive Rigor Matrix. (Hess, Carlock, Jones, and Walkup 2009) We have pulled out math examples from Hess’ Cognitive Rigor Matrix and placed them into three general ...