When we use text-based languages to exchange information, we need a default "semantic map" which is a connection (in the minds of everyone using the language) between terms in the language and the things (concepts, physical objects, ...) being discussed. In working with the RDF Model and semantic web systems, it is clear that many different techniques are being used or may be used to construct that semantic map between identifiers and their denotations.
This survey focusses specifically on the mapping of character strings functioning as identifiers, like noun phrases in English. Other approaches, such as identification-by-query, can be considered a subset of this approach, if you consider the query to be expressed in some language.
|1. Overloading Web
|HTTP (etc)URI||http://.../Creator||Both a (possibly non-existant)web page and some other object, which might be documented or formally defined on the page or on a page linked from the page.||no||Being able to talk about pages in RDF||yes||no||possible semantic confusion from overloading|
Terms in Web Page
|HTTP (etc) URI
|...22-rdf-syntax-ns#type||Some object, which might be documented or formally defined on the page or on a page linked from the page.||no||Dublin core NSs||yes||no||primary RDF approach|
|deref(HTTP URI)||*http://.../Creator||Some object which might be2 documented or formally defined on the page.||yes||RDF - requires RDF2||yes||no|
|deref("some text")||englishDenotation("The person who...")||Some object which can be unambiguously described in English||yes||machine-processable semantics||yes||yes||may be bulky; easy to misuse through laziness|
|5. Minting New
|uuid or tag URI||tag:w3.org/1:rdf:type||Some object||no||Ability to dereference;
|6. New fragid||HTTP URI refernce in deref() fragid scheme. Maybe: Ambush the short form for RDF||...rdf-syntax-ns#deref(type)||Object defined by the XML fragment type||no||messy, and messes up XML/N3 compratability. Change existing RDF.|
|7. Abandon XML for RDF||Define N3 fragid||<...rdf-syntax-ns#type>||Object||yes||RDF/XML becomes legacy|
Some of these approaches can/should be sub-categorized by what is provided in triples and what is provided at the web address, but the table is already big enough.
$Date: 2001/04/06 03:19:00 $