=Paper=
{{Paper
|id=None
|storemode=property
|title=Collaborative Metadata Editor Integrated with Ontology Services and Faceted Portals
|pdfUrl=https://ceur-ws.org/Vol-596/paper-02.pdf
|volume=Vol-596
}}
==Collaborative Metadata Editor Integrated with Ontology Services and Faceted Portals==
https://ceur-ws.org/Vol-596/paper-02.pdf
Vol-596
urn:nbn:de:0074-596-3
C opyright © 2010 for the individual
papers by the papers' authors.
C opying permitted only for private and
academic purposes. This volume is
published and copyrighted by its
editors.
ORES-2010
Ontology Repositories and Editors for
the Semantic Web
Proceedings of the 1st Workshop on Ontology Repositories and
Editors for the Semantic Web
Hersonissos, Crete, Greece, May 31st, 2010.
Edited by
Mathieu d'Aquin, The Open University, UK
Alexander García Castro, Universität Bremen, Germany
Christoph Lange, Jacobs University Bremen, Germany
Kim Viljanen, Aalto University, Helsinki, Finland
10-Jun-2010: submitted by C hristoph Lange
11-Jun-2010: published on C EUR-WS.org
Collaborative Metadata Editor Integrated with
Ontology Services and Faceted Portals
Jussi Kurki and Eero Hyvönen
Semantic Computing Research Group (SeCo)
Aalto University, School of Science and Technology, and University of Helsinki
http://www.seco.tkk.fi/, firstname.lastname@tkk.fi
Abstract. This paper presents a generic RDF metadata editor SAHA 3
for collaborative content creation and instant semantic content publish-
ing on the Semantic Web. SAHA 3 is a combination of a user-friendly
interface and rich editing tools, that are able to utilize external ONKI
ontology repositories as services. The system is integrated with a faceted
portal engine HAKO, by which the metadata can be published instantly
as a semantic faceted portal. Using the SAHA-ONKI-HAKO integrated
system, a semantic portal can be created very easily by end-users by
defining metadata schemas and related vocabularies, by annotating con-
tent, and by interactively configuring the user interfaces of the editor
and the search engine. The system is in use in several semantic web
applications and scales up to hundreds of thousands content objects.
1 Introduction
The basic process of implementing a faceted (semantic) portal [1–3] includes the
following major steps: 1) Formulate vocabularies/ontologies/facets for represent-
ing domain concepts. 2) Design metadata schemas for representing content using
(1). 3) Annotate content using (1) and (2), typically by a group of distributed
peers in a Web 2.0 fashion. 4) Select the facets (1) and create the portal with
semantic search and browsing facilities. This paper presents the tool SAHA 31
for the latter two phases. The idea is that given a set of domain vocabular-
ies/ontologies/facets and a metadata schema for annotation (phases 1 and 2), a
web-based annotation facility for distributed semantic content creation can be
created instantly without programming skills. In a similar way, a faceted portal
is automatically and instantly created online after annotating the content by
just selecting facets for searching. Again, programming is not needed but only
configuring the system using a web-based interactive interface.
We first describe the main features of the SAHA 3 metadata editor for the
content creation phase, and then the integrated faceted portal engine HAKO2
for content publishing, followed by notes about implementation and scalability.
Finally, contributions of the work w.r.t related systems are discussed, and some
application use cases are listed.
1
http://www.seco.tkk.fi/services/saha/
2
http://www.seco.tkk.fi/tools/hako/
2 SAHA 3 Metadata Editor Features
The original requirements for the web-based annotation editor SAHA [4] are
simplicity (hiding technical concepts related to markup languages and ontologies
from its user), adaptivity (to different metadata models), quality (helping and
guiding the annotator to good and correct annotations), collaboration (support-
ing distributed simultaneous annotation at different locations), and portability
(using the system on the web without installing any special software). SAHA 3 is
a completely re-written version of SAHA with the following main new features:
First, there is more support for general RDF editing, e.g. for inline editing of
nested metadata, and for extending internal vocabularies. Second, the system is
scalable to large datasets up to hundreds of thousands of objects. Third, SAHA
3 incorporates a simple publishing platform for building end-user search portals
with full-text and multi-faceted search. The whole pipeline3 from metadata edit-
ing to the end-user portal application is accessible and configurable through a
web-based interface.
During annotation, references to external ontologies are handled using the
ONKI web service interface [5, 6]. SAHA 3 utilizes autocompletion [7, 8] as a key
component to find references. When the user tries to find a concept, SAHA 3 uses
at the same time web services to fetch concepts from connected external ONKI
ontology repositories, and a local index to find locally defined concepts. Results
are shown in one autocompletion result list regardless of origin. The same query
can cover several ontology repositories at the same time. References to resources
within the project at hand and external to it (in an external ontology repository)
are transparent to the user.
The inline editor is new feature in SAHA 3 that has been found very handy by
end-users. The idea is simple: a resource referenced through an object property
can be edited inline at the right location in a small version of the editor inside the
existing editor. In this way, several levels of editors can be opened recursively
within each other, and the RDF network can be edited without moving from
one resource window to another. For example, in Figure 1 the FOAF profile of
the first author of this paper is edited, and the value of the property ”knows”
is opened inline as a similar profile editor for the second author of this paper.
Although the user interface easily becomes cluttered after a few levels, the inline
editor is a handy way to add and edit nested metadata, as in this example shows.
SAHA 3 supports collaborative simultaneous editing. Resources that are be-
ing edited by one user are locked from other users. A chat facility has been
implemented in the editor to facilitate instant discussions between peer editors
(cf. the upper right corner in Fig. 1).
3 Faceted Search Engine HAKO
A SAHA 3 project can be published through the search interface of the HAKO
portal engine. HAKO supports both free-text and faceted search [1–3]. For exam-
3
SAHA Sandbox: http://demo.seco.tkk.fi/saha3sandbox/saha3/main.shtml
Fig. 1. Editing FOAF profiles in the SAHA 3 editor. New value for ”knows” is created
inline as a new instance of a person.
ple, Fig. 2 depicts a HAKO application using the RDF store of the Kirjasampo-
system4 containing tens of thousands of instances of literary work of different
kinds. The user has entered the keyword ”tolstoi”. Free-text search is done as a
prefix search by default. On the left, one can see the hit list of 70 books and plays
related to Tolstoi distributed over the facet categories, from where the user can
refine the search either by type or by theme. The facets are configurable—the
administrator can select any object property to be a facet top category.
Apart from the facet administration, HAKO interface is actually only a front-
end to the SAHA 3 model. The configurable, shared data model (including the
indices), and the dataset used by SAHA 3 are the same as those used by HAKO.
This means that all modifications made with the SAHA 3 editor are reflected
on the HAKO interface instantly.
The system is implemented in Java on top of Spring5 framework. The data
model is based on TDB6 RDF database. Full-text search is backed by Lucene7 .
The editor interface is built using DWR8 and Dojo9 AJAX-components.
4
http://kirjasampo.fi/
5
http://www.springsource.com/
6
http://openjena.org/TDB/
7
http://lucene.apache.org/
8
http://directwebremoting.org/
9
http://www.dojotoolkit.org/
Fig. 2. SAHA3/HAKO multifaceted search interface on ”Kirjasampo”-project.
4 Discussion
SAHA 3 makes use of external distributed ONKI ontology repository services,
which is very handy when utilizing external third party ontologies and large vo-
cabularies. From the interface design viewpoint, inline editing has been found a
very useful feature. A major novelty of the system is the integration of the editor
with a portal engine in real time. The idea of instant creation of a faceted search
engine bears resemblance with SIMILE Exhibit10 . However, in our case the sys-
tem is integrated with a metadata editor, ontology services, and Semantic Web
data models, and the search technology is based on Lucene (and not JavaScript)
scaling up to very large datasets. SAHA 3 has been used in projects containing
over 100,000 instances, and it has not shown signs of slowing down, or requiring
large amounts of memory. The Tomcat server11 used runs well below 500MB
with large projects.
SAHA 3 is in production use in the HealthFinland12 system and the Kir-
jasampo project, where some 50 librarians have been annotating metadata about
tens of thousands of novels, short stories, authors, and other objects related to
Finnish literature for a semantic portal. The editor has been used is many ways
10
http://www.simile-widgets.org/exhibit/
11
http://tomcat.apache.org/
12
http://www.seco.tkk.fi/applications/tervesuomi/
in CultureSampo13 , e.g. for creating the semantic narrative descriptions of the
Finnish History Ontology14 and the Semantic Kalevala epic15 . HAKO has been
used in several industrial application demonstrations for searching documents.
Acknowledgements This work is part of the National Semantic Web Ontology
project in Finland16 (FinnONTO, 2003–2012), funded mainly by the National
Technology and Innovation Agency (Tekes) and a consortium of 38 organizations.
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