The Semantic Web aims at allowing knowledge to be freely accessed and exchanged
by software. It is now widely recognized that if the Semantic Web is
to contain deep knowledge, the need for new representation and reasoning techniques
is critical. These techniques need to find the right trade-off between expressiveness,
scalability, and robustness to deal with the inherently incomplete,
contradictory, and uncertain nature of knowledge on the Web.
The annual International Conference on Web Reasoning and Rule Systems
(RR) addresses these needs and has grown into a major international forum
for the discussion and dissemination of new results concerning Web Reasoning
and Rule Systems. The first three International Conferences on Web Reasoning
and Rule Systems (see http://www.rr-conference.org), held in Innsbruck, Austria
(2007), Karlsruhe, Germany (2008), and Chantilly, Virginia, USA (2009),
received enthusiastic support from the Web Reasoning community.
This volume contains the papers presented at the Fourth International Conference
on Web Reasoning and Rule Systems (RR 2010), which was held in
Bressanone/Brixen, Italy, September 22-24, 2010, and which continued the excellence
of the RR series. It contains nine full papers, six short papers, four
poster/position papers, one PhD paper, and two system descriptions, which
were selected out of 31 submissions following a rigorous reviewing process, where
each submission was reviewed by at least three program committee members.
The volume also contains extended abstracts of the three invited talks/tutorials.
We wish to thank all authors who submitted papers and all conference participants
for fruitful discussions. We are grateful to Georg Gottlob and Evren
Sirin for their invited talks and Axel Polleres for his tutorial at the conference.
We would like to thank the program committee members and additional reviewers
for their timely expertise in carefully reviewing the submissions. Special
thanks to Diego Calvanese and Mariano Rodr´?guez-Muro from the Free University
of Bozen-Bolzano for the organization of the conference and wonderful
days in Bressanone/Brixen. We would like to thank Jos´e J´ulio Alferes for acting
as general chair, Krzysztof Janowicz for his work as sponsorship chair, and all
sponsors for their financial support. Many thanks also to the developers of the
EasyChair conference system, which we used for the reviewing process and the
preparation of this volume.