I agree with Pat. I feel it is wrong to mix congruence, convergence and misdirection, although any one by itself is important to a full toolbox. Experimental replication has a different motivation than a bibliography. HTTP does not need any authoritative component.
--Gannon ________________________________ From: Seth Russell <russell.s...@gmail.com> To: Pat Hayes <pha...@ihmc.us> Cc: Kingsley Idehen <kide...@openlinksw.com>; "public-lod@w3.org" <public-lod@w3.org>; "public-...@w3.org" <public-...@w3.org>; "public-we...@w3.org" <public-we...@w3.org>; "dbpedia-discuss...@lists.sourceforge.net" <dbpedia-discuss...@lists.sourceforge.net> Sent: Monday, March 25, 2013 11:53 AM Subject: Re: Important Change to HTTP semantics re. hashless URIs "You can't actually get referents from HTTP protocols: for that, you have actually read (and understand) the documents that specify the referents." -- Pat Hayes I am sure that is true for some value of "You" and some value of "get". But can not some automated process actually "get" that which it uses and publishes as a reference from the proposed HTTP protocol? Seth Russell Podcasting: tagtalking.net Facebook ing: facebook.com/russell.seth Twitter ing: twitter.com/SethRussell Blogging: fastblogit.com/seth/ Catalog selling: www.speaktomecatalog.com Google profile: google.com/profiles/russell.seth On Sun, Mar 24, 2013 at 9:12 PM, Pat Hayes <pha...@ihmc.us> wrote: >On Mar 24, 2013, at 12:39 PM, Kingsley Idehen wrote: > >> All, >> >> Here is a key HTTP enhancement from Hypertext Transfer Protocol (HTTP/1.1): >> Semantics and Content note from IETF [1]. >> >> " >> 4. If the response has a Content-Location header field and its >> field-value is a reference to a URI different from the effective >> request URI, then the sender asserts that the payload is a >> representation of the resource identified by the Content-Location >> field-value. However, such an assertion cannot be trusted unless >> it can be verified by other means (not defined by HTTP). >> " >> >> >> Implications: >> >> This means that when hashless (aka. slash) HTTP URIs are used to denote >> entities, a client can use value from the Content-Location response header >> to distinguish a URI that denote an Entity Description Document (Descriptor) >> distinct from the URI of the Entity Described by said document. Thus, if a >> client de-references the URI <http://dbpedia.org/resource/Barack_Obama> and >> it gets a 200 OK from the server combined with >> <http://dbpedia.org/page/Barack_Obama> in the Content-Location response >> header, the client (user agent) can infer the following: > >I think not quite exactly as you describe it: > > >> 1. <http://dbpedia.org/resource/Barack_Obama> denotes the real-world entity >> 'Barack Obama' . >> 2. <http://dbpedia.org/page/Barack_Obama> denotes the Web Document that >> describes real-world entity 'Barack Obama' -- by virtue of the fact that the >> server has explicitly *identified* said resource via the Content-Location >> header . > >I think in fact all it can infer is > >1. <http://dbpedia.org/resource/Barack_Obama> denotes an entity, and >2. <http://dbpedia.org/page/Barack_Obama> denotes the Web Document that >describes that entity. > >You can't actually get referents from HTTP protocols: for that, you have >actually read (and understand) the documents that specify the referents. > >Still, this is all excellent progress. > >Pat > > >> >> Basically, the Toucan Affair [2][3][4] has now been incorporated into HTTP >> thereby providing an alternative to 303 redirection which has >> troubled/challenged many folks trying to exploit Linked Data via hashless >> HTTP URIs. >> >> Implementations: >> >> As per my comments in the Toucan Affair thread, our ODE [5] Linked Data >> client has always supported this heuristic. In addition, I am going propose >> implementing this heuristic in DBpedia which will simply have the net effect >> of not sending a 303 to user agents that look-up URIs in this particular >> Linked Data space. >> >> Linked Data Client implementation suggestions: >> >> I encourage clients to support this heuristic in addition to 303 with >> regards to Linked Data URI disambiguation. Implementation costs are minimal >> while the upside extremely high re., Linked Data comprehension, >> appreciation, and adoption. >> >> Links: >> >> 1. http://tools.ietf.org/html/draft-ietf-httpbis-p2-semantics-22#page-15 . >> 2. http://blog.iandavis.com/2010/11/04/is-303-really-necessary/ -- Is 303 >> Really Necessary post by Ian Davis. >> 3. http://lists.w3.org/Archives/Public/public-lod/2010Nov/0090.html -- >> mailing list thread . >> 4. >> http://linkeddata.uriburner.com/about/html/http/iandavis.com/2010/303/toucan >> -- example of heuristic handling . >> 5. http://ode.openlinksw.com -- ODE Linked Data consumer service, >> bookmarklets, and cross-browser extensions. >> 6. http://bit.ly/YxW21k -- Illustrating Semiotic Triangle using DBpedia's >> Linked Data URIs . >> >> -- >> >> Regards, >> >> Kingsley Idehen >> Founder & CEO >> OpenLink Software >> Company Web: http://www.openlinksw.com >> Personal Weblog: http://www.openlinksw.com/blog/~kidehen >> Twitter/Identi.ca handle: @kidehen >> Google+ Profile: https://plus.google.com/112399767740508618350/about >> LinkedIn Profile: http://www.linkedin.com/in/kidehen >> >> >> >> >> > >------------------------------------------------------------ >IHMC (850)434 8903 or (650)494 3973 >40 South Alcaniz St. (850)202 4416 office >Pensacola (850)202 4440 fax >FL 32502 (850)291 0667 mobile >phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes > > > > > > >
