Social Information Systems: Review, Framework, and Research Agenda Research-in-Progress Daniel Schlagwein University of New South Wales Kensington, NSW 2033, Australia schlagwein@unsw.edu.au Detlef Schoder University of Cologne Pohligstr. 1, 50969 Cologne, Germany schoder@wim.uni-koeln.de Kai Fischbach University of Cologne Pohligstr. 1, 50969 Cologne, Germany fischbach@wim.uni-koeln.de Abstract In this research-in-progress, we review the literature on an emerging new type of information systems: social information systems. Social information systems are information systems based on social technologies and open collaboration. The paper provides categories defining social information systems and a framework for existing and future research in this field of study. Keywords: Online Communities and Digital Collaborations, Framework, Literature review, Wisdom of the crowd, Social technology, Social software, Social networks, Blogs, Wikis, Crowdsourcing.