In many applications nowadays, information systems become increasingly complex, open and dynamic. They involve massive amounts of data, generally issued from different sources. Moreover, information is often inconsistent, incomplete, heterogeneous and pervaded with uncertainty. The annual International Conference on Scalable Uncertainty Management (SUM) has grown out of this wide-ranging interest in the management of uncertainty and inconsistency in databases, the Web, the Semantic Web, and Artificial Intelligence. The SUM conference series aims at bringing together researchers from these areas by highlighting new methods and technologies devoted to the problems raised by the need for a meaningful and computationally tractable management of uncertainty when huge amounts of data have to be processed. The First International Conference on Scalable Uncertainty Management (SUM'07), was held in Washington DC, USA in October 2007. Since then, the SUM conferences took place successively in Naples (Italy) in 2008, again in Washington DC (USA) in 2009, and in Toulouse (France), in 2010.

This proceedings contains the poster papers presented at the Fifth International Conference on Scalable Uncertainty Management (SUM'll) which was held in Dayton, Ohio (USA) on October 10-12, 2011.