As more schools, especially public schools, began to plan to integrate deeper learning, a group of Illinois advocates, aligned with P21, searched for assistance to scale best 21st Century teaching practices into classrooms. Already successful exemplars in the US and abroad were relying on versions of project based learning (problem-based, inquiry-based, product-making, project- based);[21] there was great variation in effectiveness. After reviewing models from multiple sources, the Illinois Consortium for 21st Century Schools determined none were adequate for systemic integration into schools or systems.