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Re: datatypes formal objection

From: Mike Dean <mdean@bbn.com>
Date: Fri, 24 Jan 2003 10:02:52 -0800
Message-Id: <200301241802.KAA10254@escher.SD.BBN.COM>
To: Brian McBride <bwm@hplb.hpl.hp.com>
cc: rdf Core <w3c-rdfcore-wg@w3.org>

This message formally summarizes my objection to the
datatyping solution adopted [1] by RDF Core [2].

I believe that datatyping is important, but the overwhelming
majority of Semantic Web users will want "global"
datatyping, where datatypes are associated with properties
in the schema/ontology, rather than "local" datatyping,
where a datatype must be associated with each value.  The
current local-only solution forces the hand of users, bloats
content, adds to the potential for inconsistencies, and
precludes otherwise-compatible schema evolution (e.g.
xsd:short to xsd:int or xsd:float).

In decreasing order, I'd prefer the following datatyping
approaches to the current one:

1) adoption of the datatyping approach used in DAML+OIL
(March 2001) [3]

2) an RDF datatyping approach that includes global
datatyping (as in Proposal F from [4]) possibly with
optional local datatyping

3) a lexical datatyping approach (as in Proposal B from [4])

4) leaving datatyping out of RDF

Given the current local-only approach, I strongly support
the following decisions made by RDF Core:

1) incorporating local datatyping within the literal node
rather than as additional graph structure (avoiding triple
bloat)

2) allowing the use of rdfs:range within a schema to
indicate the expected datatype for a property (I hope that
this can be extended to form the basis of a future global
datatyping solution)

	Mike

[1] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Oct/0131.html

[2] http://www.w3.org/2001/sw/RDFCore/

[3] http://www.daml.org/2001/03/daml+oil-index

[4] http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Oct/0049.html
Received on Friday, 24 January 2003 13:03:37 EST

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