Hello
Gregor Hagedorn a écrit :
o Are Vocabulary and Namespace synonymous terms?
Here is quotation from http://www.w3.org/TR/PR-rdf-schema (W3C's RDF schema spec.)
4.1.1. Terminology The phrase 'RDF vocabulary' is used here to refer to those resources which evolve over time; 'RDF schema' is used to denote those resources which constitute the particular (unchanging) versions of an RDF vocabulary at any point in time. Thus we might talk about the evolution of the Dublin Core vocabulary. Each version of the Dublin Core vocabulary would be a different RDF schema, and would have a corresponding RDF model and concrete syntactic representation.
o What is XML-DATA?
It's a W3C Note of 1998 by Microsoft and others, that is to a large extent implemented in IE5 (but under the name of XML Schema). W3C's "true" XML Schema, still a Working draft, is not very different from XML-DATA.
o Reading about RDF and Dublin Core as RDF application I was left confused as to what acutally is a resource. It usually seems to be assumed that it is a document, but this impression may only be due to the examples.
Here is a quotation from http://www.w3.org/TR/REC-rdf-syntax (W3C's RDF spec.) Resources All things being described by RDF expressions are called resources. A resource may be an entire Web page; such as the HTML document "http://www.w3.org/Overview.html" for example. A resource may be a part of a Web page; e.g. a specific HTML or XML element within the document source. A resource may also be a whole collection of pages; e.g. an entire Web site. A resource may also be an object that is not directly accessible via the Web; e.g. a printed book. Resources are always named by URIs plus optional anchor ids (see [URI]). Anything can have a URI; the extensibility of URIs allows the introduction of identifiers for any entity imaginable.
So we can have an URI for a plant species.
The Dublin Core is a particular vocabulary in that it has only properties; other vocabularies, like RDF schema mentioned above have properties and types.
See also my recent post about asserting in RDF a butterfly being a plant's pollinizator.
One last remark: Dublin Core is a much publicized vocabulary, but it's simple with only 15 properties. A botanical vocabulary will count hundreds of properties (from both organs and features).
Thus, in a file with several item descriptions could:
- Each item be a resource, for which a creator/editor etc. is
described using DublinCore?
- Could even the characters information within an item have different
authors? (And if yes: Is it wise to do this?)
Yes and yes. An article can have an author, and have quotations from others authors in it.
- Is there a limit to a hierarchy of RDF objects in an XML file?
No.
You can copy-and-paste this into an example.html file, and see it in Internet Explorer 5, or Mozilla, or any XHTML+CSS1 compliant browser.
Note: I assume that Mozilla does not apply to Netscape 4.7, which did not seem to be able to display the code you appended
Sad but true; I think that someday Mozilla and Netscape will merge (in functionality because the code and design is completely different).
- how and why mix several vocabularies,
I would be very interested in this one.
OK, warten Sie mal... Ich muss das überlegen.
Just say for the moment that we'll have several vocabularies by large domains:
* biological descriptions (generalities) * botany * zoology * Virology * Microbiology * geography * ecology
May the forgoten disciplins forgive me... They'll have their XML vocabularies too.
Jean-Marc