In recent years, Collective Intelligence is one of the major research subjects in Computer Science. Determining knowledge of a collective is one of the most important issues and has been considered as a subfield of Collective Intelligence. In this paper, we present a literature review on the research progress related to determining collective knowledge from autonomous indidviduals. For this aim, we will analyze some related works on determining representation of a collective, team or group knowledge, and collective intelligence. Finally, some conclusions and future directions are presented.