Advanced Design of Semantic Web Portal: ODESeW2
A. Gómez-Pérez, A. López-Cima
Laboratorio de Inteligencia Artificial
Facultad de Informática
Universidad Politécnica de Madrid
{asun, alopez}@fi.upm.es
Abstract
This poster presents a rapid web application
development framework to build semantic por-
tals. This framework is composed of reusable
views of semantic information, ontology views
and an intelligent controller, as elements of the
Model-View-Controller design paradigm.
1 Introduction
Content presentation in a portal is always a hard task,
especially in knowledge-intensive web sites where con-
tent is continuously updated and, in the case of seman-
tic portals, an expert in knowledge representation to
build the ontology is needed. To reduce the effort of
knowledge portal management we need applications
that help manage the knowledge workflow processes
(content provision and integration, content presentation
and access) and a set of tools to reduce the cost of
training a web developer in charge of managing the
semantic information.
In this paper we propose a framework to build se-
mantic portals. This framework is supported by a de-
sign paradigm currently used for building portals and
Web applications: the Model-View-Controller (MVC)
[1] design paradigm.
We are going to describe first the MVC design para-
digm, and finally how we include the MVC inside the
ODESeW2.

The Model-View-Controller is a design paradigm
used nowadays to build Web. It proposes three types of
objects: The model is a representation of the domain
information; the controller receives and interprets the
user’s actions and responds to them; the controller
manages the user’s navigation by means of a naviga-
tion model; and the view is in charge of presenting and
visualizing the model.
ODESeW2 is the second version of ODESeW [2].
ODESeW (Semantic Web Portal based on WebODE
platform1) is an ontology-based application that auto-
matically generates and manages a knowledge portal
for Intranets and Extranets. ODESeW is designed on
top of WebODE ontology engineering platform.


1 http://webode.dia.fi.upm.es/webode
ODESeW2 includes the MVC paradigm for develop-
ing semantic web portals, and this is its main enhance-
ment and the main contribution of this paper.
2 MVC in ODESeW2
ODESeW2 provides a MVC-based kit of tools to the
semantic web portal designers for producing views in
short time; these views can then be reused by an intel-
ligent controller. The intelligent controller modifies
dynamically the user’s navigation by means of inferred
information based on the user profile.
The following section presents the way in which the
three MVC elements (model, view, and controller) are
used in ODESeW2.
In a semantic portal, each object of the MVC design
paradigm has different types of resources: the model
will be compose of different domain ontologies; the
view has a library of visual components and a library
of functions to apply in views; and the controller has a
ontology based navigation model.

The model inside a portal is the domain information to
be visualized on the portal. In the case of semantic por-
tals, the model is the set of ontologies that models the
web portal domain. ODESeW2 includes two types of
ontologies: domain and cross-domain ontologies. The
domain ontology [3] serves as the basis for the content
presented on the instance Web sites to be created. So,
if the semantic web portal is used for managing R&D
projects2, the domain ontologies would include terms
such as researchers, deliverables, milestones, etc.
Cross-domain ontologies are domain-independent on-
tologies and can be used by semantic portals in differ-
ent domains. Examples are the time ontology, the unit
of measurement ontology, the event ontology, etc.

The controller uses a navigation model for controlling
the user’s navigation. It also manages all the user’s
actions, responding to the user with a specific view.
ODESeW2 provides an ontology-based navigation
model and an ontology-based permission model. We
call them portal ontologies. The semantic portal de-

2 KnowledgeWeb Portal.
http://knowledgeweb.semanticweb.org

signer uses the portal ontologies for specifying declara-
tively the navigation throughout the views.
The portal ontologies are the ontologies used by the
controller to build and maintain portals and these on-
tologies are built-in with the portal. Examples of portal
ontologies are: semantic Web service descriptor on-
tologies, navigation ontologies, user ontologies, portal
log ontologies, etc.
The most important ontology in the set of portal on-
tologies is the navigation ontology, which determines
the navigation of a user through the portal. ODESeW2
includes a navigation ontology. This ontology is com-
posed of concepts that represent a view. Each view
might have one or more relations with other views.
The controller uses these relations to control the navi-
gation of a user through different views.
All concepts in the navigation ontology have two
mandatory attributes: the attribute “precondition”,
which specifies the conditions to be satisfied when re-
questing a view; the attribute “view URL”, which speci-
fies the URL of the view implementation. Thus, the
relations between concepts in the navigation ontology
represent alternative navigation paths, and also alterna-
tive actions of a user in a view.
When the controller receives a user action from a
view, it knows in which concept it is. By means of the
users’ actions, the controller determines the destina-
tion-concept candidates; then the controller selects a
concept that satisfies the preconditions of the views. If
more than one concept satisfies these preconditions, the
controller selects the first concept and redirects to the
user the view located in the URL; this URL is specified
by the value of the attribute “view URL” in the selected
concept.

Two types of views can be generate by ODESeW2:
generics view for visualizing ontology components
independently of the domain of the portal (such as ge-
nerics views of concepts, attribute types, attributes,
relations, instances); and specific views of an ontology
components tied to how to visualize in a specific portal
(the view of any instance of concept Person, the view
of Photo attribute values, view of list of Persons group
by their Organizations). The generics views have a low
maintenance, are highly reusable but reduce the usabil-
ity of the views. The specific views fit the representa-
tion of the piece of information from the model but it is
not reusable and could be totally or partially useless
when a change in the ontology is carried out.
In ODESeW2, a mechanism to compose a view with
other views has been implemented; this mechanism
increases the reusability of views and reduces the effort
to design new views.
When the user request a composed view, the control-
ler receives from the composed view an action to in-
clude others views, then the controller acts as it has
acted with the navigation ontology, but, instead of
sending the view to the user, it sends it to the com-
posed view.
ODESeW2 can also offer the users advanced func-
tionalities based on semantic web services.
A semantic web service (SWS) is a function based
on ontologies and is located in a URL. The software
agents can locate and execute them. This artifact can be
displayed by taking the SWS definition as an instantia-
tion of the SWS definition ontology that uses as input
and output concepts of a domain ontology. Thus,
ODESeW2 can display the input form for the execution
and the output of the SWS execution.
In the following figures shows how the intelligent
controller compose a view of an instance of the concept
person and instantiates that view with a requested in-
stance from the model:
Navigation
Value of
attribute
Photo
Attributei : Valuei
Attribute Multivaluej: •Valuej1
•Valuej2
Relationi destination_instancei
Relation j : •destination_instancej1
•destination_instancej2
View of attribute email value:
Link to email
Generic view of destiantion value instance:
Link to instance info
Generic view of generic value attribute:
value
Controller
Model
(ontologies)
View of Persons:
image
Max 100 pixels
Max 100 pixels
View of attribute Photo value:
Request for
visualize an
instance of the
concept person
action viewInstance
3 Conclusions
ODESeW2 maintains the same functionalities for the
portal users, but it includes a technology very well
known by the web designer. This technology is highly
used for developing web portals, but we have adapted
this technology to retrieve and modify semantic infor-
mation stored in an ontology server. The results of ap-
plying this technology are: the reduction of the learn-
ing curve for a web designer for non-experts in the se-
mantic web; the decrease of the effort and time spent in
generating views; the freedom to generate generic or
specific views of information so that the web designer
can select between reusability or maintenance of views.
Acknowledgement
This work has been supported by the Esperonto3 (IST-
2001-34373) and KnowledgeWeb4 (IST-2004-507482)
project.
References
[1] G. Erich, R. Helm, J. Vlissides, R. Jhonson, Design
Patterns: Elements of Reusable Object-Oriented Soft-
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[2] O. Corcho, A. Gómez-Pérez, A. López-Cima, V.
López-García, M.C. Suárez-Figueroa. ODESeW. Auto-
matic generation of knowledge portals for intranets
and extranets. ISWC 2003.
[3] Y. Jin, S. Decker, G. Wiederhold. OntoWebber:
Model-Driven Ontology-Based Web Site Management.
SWWS 2001.

3 http://www.esperonto.net
4 http://knowledgeweb.semanticweb.org