14 1094-7167/04/$20.00 © 2004 IEEE IEEE INTELLIGENT SYSTEMS
Published by the IEEE Computer Society
G u e s t E d i t o r s ’ I n t r o d u c t i o n
Semantic Web Services
Terry Payne, University of Southampton
Ora Lassila, Nokia
T he Semantic Web1 is a vision of a new architecture for the World Wide Web, char-acterized by the association of machine-accessible formal semantics with more
traditional Web content. The Semantic Web’s original motivations were to increase automa-
tion in processing Web-based information and to improve the interoperability of Web-
based information systems. The development of representational issues and logical
frameworks (such as OWL2) will take us only so far;
to fully realize this vision, we must tackle behavioral
issues (for example, interactions between “Semantic
Web agents”). Serendipitous interoperability—that is,
the unarchitected, unanticipated encounters of agents on
the Web—is an important component of this realization.
Semantic Web techniques, which consist of apply-
ing knowledge representation techniques in a distrib-
uted environment (potentially on a Web-wide scale),
have proven useful in providing richer
descriptions of Web resources. Seman-
tic Web Services, as a new research
paradigm, is generally defined as
the augmentation of Web Ser-
vice descriptions through
Semantic Web annotations,
to facilitate the higher au-
tomation of service dis-
covery, composition, invo-
cation, and monitoring in
an open, unregulated, and
often chaotic environment
(that is, the Web). Several
research and “prestandard-
ization” activities in Semantic
Web Services have emerged, the
best known perhaps being the
DAML-S/OWL-S work3 devel-
oped in the DAML
research program.
Semantic Web
Services represent an important step toward the full-
blown vision of the Semantic Web, in terms of utiliz-
ing, managing, and creating semantic markup.
The relationship between the Semantic Web and the
current Web Service architecture depends on your view-
point. In the near term, the deployment of Web Services
is critical, and Semantic Web techniques can enhance
the current service architecture. In the longer term, the
Semantic Web vision itself becomes more interesting,
with Web Services offering a (hopefully) ubiquitous
infrastructure on which to build the next generation of
deployed multiagent systems.
This issue features seven articles based on submis-
sions to the 2004 AAAI Spring Symposium on Seman-
tic Web Services (held at Stanford University on 22–24
Mar. 2004). These articles represent the best and most
representative work in the field. They address several
important aspects of Semantic Web Services, from dis-
covery, to planning and composition of services, to
mapping between different ontological representa-
tions, to the more pragmatic issues of access policies
and security.
Because services can randomly appear and be with-
drawn, we need a framework that describes their func-
tionality and behaviors and that can subsequently be
used for location. Much conventional research in this
area has focused on representing services from an arti-
ficial intelligence perspective, which uses functional
descriptions oriented toward supporting composition
through AI-based planning. In “Value Webs: Using
Ontologies to Bundle Real-World Services,” Hans