RDF Schema design pb: inheritance of properties

Hello

We are designing XML vocabularies for the description of biological
species.
See :
http://jmvanel.free.fr
and Taxonomic Databases Working Group - Structure of Descriptive Data
<TDWG-SDD@USOBI.ORG> (mailing list)
archive available at http://usobi.org/archives/tdwg-sdd.html

This is a large project: 250 000 species of plants, 1 000 000 of
insects, relations beetwen plants and insects, etc...


There is a containment hierarchy (e. g. a flower contains petals) which
raises no problems in XML.

But there is an inheritance hierarchy that I don't know how to handle
using W3C's specifications alone.
A genus has properties values (e. g. flower/petals/color = 'white' )
that MUST be inherited by the species in this genus. The properties
values of a genus CAN be overriden by some species in this
genus.

It seems that the "refines" property in XML Schema would bring the
desired semantics, together with the "Schema Information Set
Contribution: augmentations to instance information sets which follow as

a consequence of schema-validation". But the uncomplete state of the W3C
document makes me unshure.

Although RDF and RDF Schema's data model are very promising, allowing to
:
- make links between plants and insects,
- state properties about properties (some are morphological, others are
chemical, etc ...) ,

I don't see anything clearly specified in RDF and RDF Schema for
inheritance of properties.

Would this be a solution:
- each instance of genus is a rdfs:Class, e.g. all daisies belong to
(are rdfs:subClassOf) the genus Chrysantemum;
- a genus has Class properties,
- a species, instance of species, and subClassOf a genus, redefines some
of the genus' properties, overrides the other properties, and adds
properties unspecified by the genus.

Sample RDFS:

<rdfs:Class ID="Chrysantemum"/>
   <rdfs:subClassOf rdf:resource="http:botany.org/taxonomy#genus"/>
   <flower><petals>
    <color>white</color>
    <number>10--40</number>
  </petals></flower>
</rdfs:Class>

<species>
  <rdfs:subClassOf rdf:resource="Chrysantemum" />
    <name>maximum</name>
    <flower><petals><color>yellow</color>
    <!-- here do we inherit from <number> of Chrysantemum? -->
  </petals></flower>
</species>


Info. for computer men: biology has a hierarchic classification of
species whose 4 lowest levels are:
order
family
genus
species

Received on Tuesday, 30 November 1999 17:07:05 UTC