- From: Henry S. Thompson <ht@inf.ed.ac.uk>
- Date: Thu, 20 Mar 2008 18:46:35 +0000
- To: Richard Cyganiak <richard@cyganiak.de>, leo.sauermann@dfki.de
- Cc: www-tag@w3.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I've had a quick try at redrafting section 3.1 of https://gnowsis.opendfki.de/repos/gnowsis/papers/2006_11_concepturi/html/cooluris_sweo_note.html#distinguishing 3.1 Distinguishing between representations and descriptions Above we assumed that there is a distinction between accessing web documents on the one hand and accessing descriptions of resources on the other. The question is where to draw the line between the case where either is possible and the case where _only_ descriptions are available.. According to W3C guidelines ([AWWW], section 2.2.), we have a Web document which we can access directly (there called information resource) if all its essential characteristics can be conveyed in a message. Examples are a Web page, an image or a music recording. The URI identifies both the entity and indirectly the message that conveys the characteristics. There are of course also entities whose characteristics can not be conveyed in a message. For such entities, _only_ descriptions of the entity are available for retrieval It's crucial to not be confused by the fact that a Web document may itself often describes some other entity, which is not itself a Web document. For example the person Alice (not a Web document) is described by her homepage (a Web document). Bob may not like the look of the homepage, but fancy the person Alice. Since our advice above is to only use a 200 response code when a Web document has been accessed, it follows that when designing URIs and configuring web servers we need to know when we're talking about identifying Web documents as such and when we're talking about descriptions of entities, whether they are Web documents or not. Our recommendation is to err on the side of caution: Whenever an object of interest is not clearly and obviously a document (all its essential characteristics can be conveyed in a message), then it's better _not_ to respond with a 200 to a request for the URI identifying it. [Hmm, this is probably useless, but maybe it helps a bit] - -- Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh Half-time member of W3C Team 2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440 Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk URL: http://www.ltg.ed.ac.uk/~ht/ [mail really from me _always_ has this .sig -- mail without it is forged spam] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) iD8DBQFH4rELkjnJixAXWBoRAi7eAJ0WAVsSsaMmA1PdTJywRY+xHh3c8QCfSRDg oF1LyLv8mYlN3VH5wTSkubk= =ACGc -----END PGP SIGNATURE-----
Received on Thursday, 20 March 2008 18:47:19 UTC