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Towards Social Descriptions of Services
Nikos Loutas 1,2 , Vassilios Peristeras 1 , Konstantinos Tarabanis 2
1 Digital Enterprise Research Institute, NUI Galway
(firstname.lastname)@deri.org
2 Information Systems Lab, University of Macedonia, Greece
Abstract
This work aims to close the gap between two
phenomenically contradictory service annotation
paradigms: traditional semantic service models and the
emerging social annotation of services. It aims to (i)
extend service description models to include the
bottom-up user-driven social descriptions of services,
and (ii) facilitate the semantic interlinking between
services annotated using different semantic models.
1. Introduction
The history of efforts to describe services in three
successive eras: the syntactic, the semantic and the
social one. Each of these eras took the expressivity of
service descriptions one step further.
The ‘syntactic era’ dates back to the first days of
SOA developments. The need for a standardized format
for describing service interfaces and capabilities
resulted in WSDL. But WSDL remains at the syntactic
level and thus cannot incorporate rich service-related
information that could be utilized in order to improve
the quality of service provision.
The ‘semantic era’ emerged in the late 90’s
influenced by the vision of the Semantic Web.
Semantically-enhanced service descriptions promised to
enable and to facilitate the dynamic discovery,
invocation, execution, composition and monitoring of
services. This led to the definition of various noninteroperable
semantic service models such as OWL-S,
WSMO, SA-REST and SAWSDL. However, their high
complexity and cost have prevented to date the
industrial adoption of semantic service descriptions.
Additionally, existing service descriptions (both
syntactic and semantic ones) are provider-oriented
constructs and leave the users’ perspective outside.
They assume that the user has a passive role, limited to
the consumption of the services, and that the semantic
description of the service is created exclusively by the
service provider.
The ‘social era’ is largely related to the
establishment of the Social Web as a new computing
paradigm, which capitalizes largely on collective
intelligence, with semantics emerging in a bottom-up
fashion, directly from the users. This has a direct effect
on the description of services as well.
2. The Service Description Metamodel
The service description metamodel (SDM) extends
existing semantic service descriptions in order to
include the user’s perspective i . We proved that all
semantic service models can be mapped to SDM.
SDM defines the following: A service provider
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provides a service. A service client uses a service. A
service is described by an extended semantic
description co-created by the service provider and the
service client. The service description comprises of
provider-driven and user-driven service aspects. There
are five different types of provider-driven service
aspects: information model, functional descriptions,
non-functional descriptions, behavioural descriptions
and technical descriptions. There is one type of userdriven
service aspects: social descriptions.
3. The Reference Service Model
The reference service model (RSM) for the Web of
Services facilitates the semantic interlinking between
heterogeneous semantic services and the development
of socially-aware semantic services.
RSM comprises of the following: service, service
input, service output, service context, service logic,
service provider, service client and service feedback.
A service provider provides a service. A service
requires one or more service inputs. A service produces
one or more service output. A service implements a
service logic. A service is executed in a service context.
A service receives service feedback. A service client
consumes a service. A service client obtains the service
output. A service client gives service feedback. A
service client adapts the service context.
4. Expected Benefits
This work strengthens the position of the users in
service provision by facilitating their participation in
the co-creation of service descriptions. It contributes to
the conceptual modeling of services, being the first
systematic modelling effort to include social
descriptions in service models. It lowers the semantic
interoperability barriers and contributes to the
reusability of existing services described using different
semantic service models. Social descriptions provide
new insights on service search and discovery, design,
composition, recommendation, personalization and
marketing. It is a technology-independent effort and can
be combined with any (semantic) service model and
with SOAP-based and RESTful services alike. It is thus
expected to contribute to the uptake of semantic
services and improve the quality of service provision.
Acknowledgments. This work is funded in part by
Science Foundation Ireland under Grant No.
SFI/08/CE/I1380 (Lion-2).
i N. Loutas, V. Peristeras, K. Tarabanis, “Rethinking the Semantic
Annotation of Services”, In 7th ICSOC/ServiceWave Workshops,
LNCS, Vol. 6275, pp. 540-549, 2009 Stockholm, Sweden