The only possibility for federally structured organizations and communities to enable consistent views on their meta-data and contents is to establish methods to gather the meta-data from the distributed peers, integrate it into a common conceptual model and ¯nally make it accessible to humans and software systems. We present the approach taken to implement this strategy for the over 2000 a±liated organizations of the Bavarian Lutheran Church. It showcases how di®erent Semantic Web standards, vocabularies, and methodologies can be coherently integrated into a consistent framework delivering added value to the large audience of participating peers.
The Lutheran Church in the German federal state Bavaria has around 2000 af¯liated clerical, cultural or charitable communities, organizations, and societies. All of them have their separate organizational structure with di®erent spheres of activities, websites, contact information and various other information.
Unlike strictly hierarchical structured organizations such as business cooperations, for organizations which pro¯t most from their social and cultural diversity, such as the Lutheran Church, the usage of a single uni¯ed data model or system (e.g. content or knowledge management system) to manage such information will be impossible.
Nevertheless it is highly desirable to give people an overview of lutheran organizations, activities, and content related to a geographical region or to a speci¯c topic. Thus a web portal was requested interlinking all these resources and making them easily accessible for interested parties within and outside the Lutheran Church of Bavaria.
To reach this aim a Semantic Web application was envisioned, which collects information and meta data from distributed sources with diverse ownerships, integrates them into a common extensible conceptual model, which should be ¯nally represented on the Web, exposing as many semantic relations as possible. An additional aim is to establish a meta-data initiative focused on religious related content and to support individuals and organizations accordingly with its application.
The implementation of a prototype was realized by the department
\Vernetzte Kirche" within the Bavarian Lutheran Church in cooperation with the
University of Leipzig. The implementation is based on the Semantic Web
application development framework Powl [
The \Vernetzte Kirche" use case of Semantic Web technologies is presented here as follows: We ¯rst describe the information structure used to represent the various types of information. In Section 3 we give account how this information structure is populated with concrete data from the distributed, heterogeneous sources. We elaborate in Section 4 on ways to make this information accessible to humans and software systems. Finally we give some concluding remarks and an outlook on planned enhancements in Section 5. 2
The ¯rst challenge was to ¯nd an integrated conceptual model for the information about relevant organizations and resources, which should be °exible enough to allow consistent integration of new information as it arises.
Schema ontologies aligned … … … Instance ontologies Syncronize
Authenticate Syndicate
Geo
Vocabularies
Because of the heterogenic structure of this information an ontology seems to
be more adequate to capture it than for example a ¯xed database schema. Such
an ontology was developed in OWL [
The main concepts (or classes) were quickly identi¯ed: Organizations and Content. The class Content is categorized into the subclasses Images, Books, News, Events and Journals; additional classes can be added as needed. The classi¯cation of organizations though is more complicated, since every organization can be classi¯ed along di®erent taxonomies: { Regional, ² By German administrative units (federal state; district; region; community or city), ² By established regional church structure (regional church; deanery; clerical district; religious community), { Sphere of activity (e.g. education, arts, and culture; administration; souls care), { Type of organization (e.g. choir; community; publishing house), { Topics and keywords.
For the spheres of activity, types of organizations, topics and keywords
separate classes containing taxonomies of instances are introduced. The taxonomic
structure is encoded using a functional object property subTypeOf having the
respective class as domain and range. An elaborated keyword taxonomy was
created using the SKOS [
Address information for a speci¯c organization is used in conjunction with the data of OpenGeoDB 2 to calculate its geographical coordinates and relate the instance to the regional classi¯cations. The geographical vocabulary (with the namespace http://www.w3.org/2003/01/geo/wgs84_pos#) is used here to capture this information within the ontology.
For initial acquisition of instance data Powl's feature to import rows from an Excel sheet as instances was very bene¯cial, since most of the information was already available within conventional O±ce documents. As Powl enables the customized generation of reports in spreadsheet compatible formats the traditional storing of information within Excel documents became needless.
The complete ontology schema is available from the \Vernetzte Kirche" web site 3 and intended to be reusable by other established regional churches or similar federally structured associations. Currently, it contains around 70 classes and 40 properties. 3
To populate the information structure presented in the last section, instance data
has to be continuously acquired, synchronized, or updated. For content related
meta-data, specialized acquisition methods have been developed:
1 http://www.fotoBayern.de
2 http://opengeodb.de/
3 http://www.vernetzte-kirche.de
{ Images - meta data is envisioned to be integrated into web-accessible image
¯les according to the proposed \Vernetzte Kirche" classi¯cations. Common
image formats, such as JPEG or PNG o®er the ability to save meta-data
within the ¯le in custom text formats. Images and meta-date thus can be
gathered from speci¯ed web sources, such as the photo service \FotoBayern".
{ News - such as from publications as the \Sonntagsblatt"4 or the lutheran
press service EPD5 are syndicated by accessing respective RSS feeds. News
feeds are encouraged to use the \Vernetzte Kirche" or IPTC classi¯cations
to tag their news.
{ Events - for events as concerts, religious services or courses a specialized
database and administration portal \Evangelische Termine"6 existed.
Information is exchanged by establishing a synchronization between the database
schema and the ontology in the spirit of D2RQ [
To continuously acquire instance data about organizations a distributed ownership strategy was selected: 1. Organizations integrate meta information about them self inside the HTML header of their website. 2. A crawler regularly gathers this meta data and updates existing instances accordingly.
To ease the task of integrating meta information into the organization
websites a meta-tag generator was developed. A publisher thus has to complete a
simple web form to generate an HTML header snippet for integration into the
organizations website. The integration of meta data and its extraction is
implemented according to the GRDDL mechanism [
ELKB, semantische Suche" /> <meta name="robots" content="follow" /> <meta name="revisit-after" content="20 days" /> 4 http://www.sonntagsblatt.de 5 http://epd.de 6 http://www.evangelische-termine.de/
By using attributes of commonly used vocabularies (such as Dublin Core [
Since some, user and organization related information, is held in an LDAP directory, for extranet authentication purposes, a synchronization between distinct instance and property values and LDAP nodes was implemented.
The overall instance data related to the Bavarian Lutheran Church contains currently around 5,000 instances, accounting for 60,000 triples. 4
After ¯lling the meta-data repository, this information should be shared with
\human" and arti¯cial agents. For machine consumption access is provided by
Web-Services or the NetAPI [
The user interface of the web portal consists of two di®erent types of pages: overview pages with lists of instances and detail pages, exposing the attributes of a distinct instance with all the speci¯cs. The overview pages for organizations follow a three column layout (as depicted in Figure 2): { the left part contains the regional ¯ltering options (by German administrative units or established regional church structure), { in the middle part the list of organizations in the selected region (and according to optionally applied ¯lters) is presented, { on the right the results can be ¯ltered according to available taxonomical categorizations available for organizations in the selected region.
By choosing the details link for an organization in the list the user reaches a web page combining all information about that organization. The calculated geo coordinates for a speci¯c organization are used to render a map with the location highlighted and to get a list of nearby organizations.
A full-text search is provided, to query the data for literal descriptions containing the search string. Results are grouped by the instances and ordered by the occurrence frequency of the search string. Search results may be ¯ltered to contain only resources which are instances of a distinct class (e.g. restrict the search to organizations or books) or which are described by the literal only in conjunction with a distinct property (e.g. dc:author). This semantic search has signi¯cant advantages compared to conventional full-text searches, since it provides important feedback to the searching user on how to successfully re¯ne the search.
The portal framework further allows to export or extract complete
metadata sets or information fragments by NetAPI [
Semantic Web knowledge representation standards and especially the generic Semantic Web application development framework Powl enabled the project \Vernetzte Kirche" to rapidly develop an initial version of the ontology and a prototype of the web portal with minimized resource and cost demands.
Though already publicly accessible the application is still in Beta stage. First experiences with real users showed the practicability of the approach. Currently, it is worked on the transition into an easy to use, productive, scalable industry strength system. To achieve this goal usability and documentation as well as the stability of the crawling solution has to be improved further. It is additionally planned to implement enhanced client-side meta-data annotation and extraction methods with the focus for usage within the \Vernetzte Kirche" project.
Summarizing we can state that the project showcases how di®erent Semantic Web standards, vocabularies, and methodologies can be coherently integrated into an consistent framework delivering added value to a large audience of participating peers.