[Tdwg-tag] RDF instead of xml schema

Donald Hobern dhobern at gbif.org
Fri Mar 24 23:58:03 CET 2006


I can understand your angst, but I would like to suggest that XML schema
actually only really provides good support for some aspects of OO modelling.
Extending classes is a real problem.

A data model encoded in RDF can still make use of an ontology language to
provide greater rigour in the way that objects are defined.

As was indicated in some of the earlier messages here, it is even possible
to put together a data model which looks fundamentally just the same as one
defined using XML schema but which is using RDF technologies under the
covers and which consequently is easier to extend than XML schema.

For me however the biggest factors of importance in a revision of our data
models would be:

1. A cleaner separation between different object classes (not all versioned
in a single schema).

2. A good model to support easy extension (using a multiple inheritance
approach) so that different (potentially overlapping) communities can add
extra information in the ways that best suit them.

3. An underlying ontology that is sufficient for us at least to identify the
object class of each record.

RDF technologies are an excellent way to do this.  GML has managed to
produce many of the same features, but has probably done so largely by
replicating the essentials of RDF modelling.


Donald Hobern (dhobern at gbif.org)
Programme Officer for Data Access and Database Interoperability 
Global Biodiversity Information Facility Secretariat 
Universitetsparken 15, DK-2100 Copenhagen, Denmark
Tel: +45-35321483   Mobile: +45-28751483   Fax: +45-35321480

-----Original Message-----
From: Tdwg-tag-bounces at lists.tdwg.org
[mailto:Tdwg-tag-bounces at lists.tdwg.org] On Behalf Of Gregor Hagedorn
Sent: 24 March 2006 18:37
To: Tdwg-tag at lists.tdwg.org
Subject: [Tdwg-tag] RDF instead of xml schema

Hi all,

RDF to me appears on a level of abstraction making it very hard for me to 
follow the documentation and discussion. Most of the examples are embedded
an artificial intelligence / reasoning use cases that I have no experience 

I am a biologist and I feel comfortable with UML, ER-modeling, xml-schema-
modeling, and - surprise - relational databases. I believe many others are
well - how many datastores are actually build upon RDBMS technology?

To me xml-schema maps nicely to both UML-like OO-modeling and Relational
I can guess about the advantages of opening this all up and seeing the world
a huge set of unstructured statement tupels. But it also scares me.

Angst is a bad advisor. But then if only a minority of the current few
involved can follow on the RDF abstraction level. A few questions I have:

* Would we be first in line to try rdf for such complex models as

* Do Genbank/EMBL with their hundreds of employees and programmers use rdf? 
Internally/externally? The molecular bioinformatics is probably 1000 times 
larger than our biodiversity informatics.

* Why are GML, SVG etc. based on xml schema and not RDFS? Is this just 

* Are there any tools around that let me import RDF into a relational
(simple tools for xml-schema-based import/export are almost standard part of

databases now, or you can use comfortable graphical tools like Altova 

-- I am just trying to test some tools to help me to visualize RDFS
(like Roger has send around) on a level comparable with the UML-like
editors (Spy, Stylus, Oracle, etc.) I will try Altova SemanticWorks and
over the next week. The screenshot seem to be about AI and semantic web much

more than about information models (those creatures where you try to
the world to make it manageable...).

Gregor Hagedorn (G.Hagedorn at bba.de)
Institute for Plant Virology, Microbiology, and Biosafety
Federal Research Center for Agriculture and Forestry (BBA)
Königin-Luise-Str. 19           Tel: +49-30-8304-2220
14195 Berlin, Germany           Fax: +49-30-8304-2203

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