- From: Jonathan A Rees <rees@mumble.net>
- Date: Sat, 31 Mar 2012 10:54:09 -0400
- To: Michael Brunnbauer <brunni@netestate.de>
- Cc: Norman Gray <norman@astro.gla.ac.uk>, Tim Berners-Lee <timbl@w3.org>, public-lod community <public-lod@w3.org>
On Sat, Mar 31, 2012 at 8:05 AM, Michael Brunnbauer <brunni@netestate.de> wrote: > > hi all > > The document at http://www.w3.org/2001/tag/doc/uddp-20120229/ uses the > term X (a sequence of octets + media type) is a representation of Y (an entity). > > I have a question: Can two different entities have the same representation ? I've never heard anything say anything that would rule this out. Well, on second thought, in conversation I've heard people give a theory that representations being "on the wire", which would make them events, which occur in space and time, thus cannot "happen twice". But this idea does not follow from 2616 or 3986 or AWWW and does not have anything like consensus. I always thought that Content-location: suggested this situation, where you have two URIs and two resources, and a representation that is of both, where the first resource might have *additional* representations, and the second doesn't. This seems tidy to me, but it's just my theory. > If not, we can define an IR as a thing for which there is at least one > sequence of octets + media type that is a representation of it because it's > essential characteristics would be conveyed in that message. The term IR > would not have much value in this case as it would not be a term of it's own. That is: an IR is something that has a representation. I think this has been suggested several times. Unfortunately "information resource" has a definition in AWWW and I don't see the merit in redefining the term rather than introducing a new term. However I believe I have heard this suggestion, or something like it, before, from several sources, so it's not completely out of the question. It would be nice in a way because it would make HR14a completely vacuous. This is what I call "opt in" because you wouldn't be able to assume that what you GET is content (Tim's word, my "instance"). > If yes, I could have a lossy compression algorithm that makes the same > sequence of octets out of two different images and still have a representation > of those images when I GET them. > > I think all the difficult questions (or the nitpicking, if you want) do not > go away if we drop the term IR. They also lie in the question "does this > URI denote what it accesses" or "is this message a representation of the > entity" or "do I serve the content of this sucker". I'm glad you say this. I agree that the "when is X content of Y" question remains, although to me it's not such a difficult question (it remains for me to convince others of this). Best Jonathan > Regards, > > Michael Brunnbauer > > On Wed, Mar 28, 2012 at 11:35:04PM +0200, Michael Brunnbauer wrote: >> >> Hallo Norman, >> >> > -Regardless of how you define IR, everything that denotes what it accesses >> > should lie in IR. >> > >> > -Putting something in NIR therefor also answers the question if it denotes >> > what it accesses with "no" by entailment. >> >> I have worded this very badly. We are talking about things and names of things. >> This should be: >> >> For all URIs U: denote(U) = access(U) -> denote(U) a IR >> >> It follows: For all URIs U: denote(U) not a IR -> denote(U) != access(U) >> >> > -There may or may not be IRs that do not denote what they access. >> >> And this should be: >> >> There is a URI U where: denote(U) a IR and denote(U) != access(U). >> >> Now if a am allowed to mint a URI that 303's to your homepage and your >> homepage is an IR, such an URI must exist: >> >> U1 = Your URI for your homepage >> U2 = My URI for your homepage >> denote(U1) a IR >> denote(U2) != access(U2) >> denote(U1) = denote(U2) thererfor denote(U2) a IR and denote(U2) != access(U2) >> >> I think I'll stay out of this discussion from now :-) >> >> Regards, >> >> Michael Brunnbauer >> >> >> -- >> ++ Michael Brunnbauer >> ++ netEstate GmbH >> ++ Geisenhausener Straße 11a >> ++ 81379 München >> ++ Tel +49 89 32 19 77 80 >> ++ Fax +49 89 32 19 77 89 >> ++ E-Mail brunni@netestate.de >> ++ http://www.netestate.de/ >> ++ >> ++ Sitz: München, HRB Nr.142452 (Handelsregister B München) >> ++ USt-IdNr. DE221033342 >> ++ Geschäftsführer: Michael Brunnbauer, Franz Brunnbauer >> ++ Prokurist: Dipl. Kfm. (Univ.) Markus Hendel > > -- > ++ Michael Brunnbauer > ++ netEstate GmbH > ++ Geisenhausener Straße 11a > ++ 81379 München > ++ Tel +49 89 32 19 77 80 > ++ Fax +49 89 32 19 77 89 > ++ E-Mail brunni@netestate.de > ++ http://www.netestate.de/ > ++ > ++ Sitz: München, HRB Nr.142452 (Handelsregister B München) > ++ USt-IdNr. DE221033342 > ++ Geschäftsführer: Michael Brunnbauer, Franz Brunnbauer > ++ Prokurist: Dipl. Kfm. (Univ.) Markus Hendel
Received on Saturday, 31 March 2012 14:54:38 UTC