Common Core has released an open letter to promoters of a 21st century skill-based curriculum, and the organization P21 in particular, entitled “A Challenge to the Partnership for 21st Century Skills.” The letter argues that a curriculum based around skills, such as the one espoused by the Partnership for 21st Century Skills, marginalizes knowledge and undermines the liberal education that American students need. Before any more damage is done, the Partnership should “reshape their effort by putting knowledge and skills together at the core of their work.” Read the full text here.