This chapter describes a systematic approach to studying knowledge commons as an institutional mode of governance of knowledge and information resources. “Knowledge commons” refers to an institution (commons) for governing production, use, and/or preservation of a particular resource (knowledge or information, including resources linked to innovative and creative practice). “Commons” refers to a form of community management or governance. It applies to a resource, and it involves a group or community of people who share access to and/or use of the resource. “Commons” is the institutional arrangement of these elements and their coordination via combinations of law and other formal rules; social norms, customs, and informal discipline; and technological and other material constraints. “Knowledge” has broad scope, in order to permit knowledge commons researchers to capture and study a wide range of commons institutions and to highlight the importance of examining knowledge commons governance as part of dynamic, ecological contexts.