- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Thu, 6 Feb 2003 12:07:42 -0500
- To: webont <www-webont-wg@w3.org>
>From: "Raphael Volz" <volz@aifb.uni-karlsruhe.de> >To: "Jim Hendler" <hendler@cs.umd.edu> >Cc: "Guus Schreiber" <schreiber@swi.psy.uva.nl> >Subject: RDF SCHEMA REVIEW (ACTION VOLZ) >Date: Thu, 6 Feb 2003 16:48:08 -0000 >X-Priority: 3 (Normal) >Importance: Normal >X-Spam-Status: No, hits=1.0 required=5.0 > tests=SPAM_PHRASE_01_02,SUBJ_ALL_CAPS > version=2.43 >X-Spam-Level: * > >Hi - > >sorry for writing to you instead of the group but >I am not allow to post since I am sitting 800 Miles >up north and the Outlook Web interface cannot be stopped >from generating HTML instead of plain text. > >----------------------- >RDF Schema Review for WebOnt >RAphael Volz, FZI, Karlsruhe >February 6, 2003 >---------------------------- > >Status of Doc: >- Differences to 03/27/2000 version >should be made explicit (e.g. in an Appendix) > >Section 1 (Intro): >- Why is this language called RDF Schema and >not RDF Vocabulary Description Language >- The examples given in RDF PRIMER should also >be given here (for sake of completeness and to >facilitate reading and understanding) >- "This document is intended to provide a clear >specification to those who find RDF Semantics >daunting" --> it didn't make things clearer to me, unfortunally... >- The statement that 1" [...] RDF vocabulary description language >is similar to a type systems of OO programming languages >such as Java" is simply wrong and very misleading, the only >thing common is the use of the word "Class". > >Section 2 (Classes) >Paragraph 6: "All Datatypes are classes" >--> Does this mean that it's members can be enumerated ? > >2.5 >The intention of XMLLiteral is unclear from the >text, point to appropriate other RDF document or >explain more. >- What does it mean if >XML Document instance is again valid RDF ?. >- Say that fully normalized/Canonical XML is required. > >Section 3 (Property) >Why do you specify two different ELements >subPropertyOf and subClassOf > >-3.5. What happesn with domain/range constraints >stated on super-properties wrt. to subproperties. >No behavior specified for that. > >Section 4: >This section is fatal. Why bother with any specification >or formal semantics at all, when every application is >allowed to do what it wants anyway. A RDFS does never >specify limitations on "types of values", instead it >facilitates lazyness of the user and tries to remedy >missing information by simply entailing it. >I thought that the RDF Semantics intention was to say >how an application should understand RDF data. It >is also unclear what the semantics of custom vocabulary >is, does it at least have the same semantics as the >original vocabulary of which is was derived, e.g. >if I say myRange subPropertyOf range. If this is not >the case, why should a write a schema at all, why not >base the semantics of my application simply on >string values, why should I bother to tell anyone about >that semantics ? > >Section 5: >Does the lack of formal specification on Collections (e.g. >that Seq represents a total order on it's elements) mean >that processors may validly ignore i ? > >Section 5.4.3: >Why do I still need value, why not represent structured >information as XML using XMLLiteral ? > > >General resume: >The document should clarify whether it endorses a specific >semantic interpretation or whether it only declares a >couple of names that others may find useful. > >Mit freundlichen Grüßen, >Best regards, > >Raphael Volz >Institut AIFB, Universität Karlsruhe >http://www.aifb.uni-karlsruhe.de/WBS/rvo >volz@aifb.uni-karlsruhe.de > >WIM, FZI Karlsruhe >http://wim.fzi.de/ >volz@fzi.de > >Fax: 01212-5-470-17-365 -- Professor James Hendler hendler@cs.umd.edu Director, Semantic Web and Agent Technologies 301-405-2696 Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax) Univ of Maryland, College Park, MD 20742 240-731-3822 (Cell) http://www.cs.umd.edu/users/hendler
Received on Thursday, 6 February 2003 12:07:59 UTC