{"id":451,"date":"2004-09-10T12:29:00","date_gmt":"2004-09-10T16:29:00","guid":{"rendered":"http:\/\/www.markbaker.ca\/wp\/2004\/09\/10\/dave-orchard-on-the-semantic-web\/"},"modified":"2004-09-10T12:29:00","modified_gmt":"2004-09-10T16:29:00","slug":"dave-orchard-on-the-semantic-web","status":"publish","type":"post","link":"http:\/\/www.markbaker.ca\/blog\/2004\/09\/dave-orchard-on-the-semantic-web\/","title":{"rendered":"Dave Orchard on the Semantic Web"},"content":{"rendered":"<p>Kudos to Dave for pulling up his socks and\n<a href=\"http:\/\/www.pacificspirit.com\/Authoring\/Compatibility\/OWLRDFExtensibility.html\">discovering<\/a>\nwhat Semantic Web technologies have to offer first hand &#8211; you know, all that\nwonderful extensible goodness I&#8217;ve been\n<a href=\"http:\/\/www.markbaker.ca\/Talks\/2004-xmlself\/slide1-0.html\">going on about<\/a>\nafter discovering it for myself.<\/p>\n\n<p>He talks about a perceived problem here &#8230;<\/p>\n\n<blockquote>\nIn order to prevent an area code, I need to add the area code with a cardinality of 0. Now I think this is a pretty big problem. The whole Semantic Web world view of open content models comes and bites us here. The rough assumption is that if a property isn&#8217;t specifically exluded, it might be related to the thing.\n<\/blockquote>\n\n<p>That&#8217;s not quite right.  It&#8217;s one thing to look at the information space that\nis the Web\/Sem-Web and see two separate but related resources (e.g. the PO and\nthe customer), but it&#8217;s something else entirely to look at a <em>message<\/em> on\nthe Web and conclude that there might be some data elsewhere which is intended to\nbe communicated.  That&#8217;s where\n<a href=\"http:\/\/www.ics.uci.edu\/~fielding\/pubs\/dissertation\/rest_arch_style.htm#sec_5_1_5\">self-description<\/a>\ncomes in, and it prescribes that if a message arrives with a PO and without a\ncustomer, then the customer information is not part of the message, as you\nrequire.  What Bijan seems to be talking about is the former, not the latter,\ni.e. to avoid\n<a href=\"http:\/\/esw.w3.org\/topic\/ClosedWorldAssumptions\">closed world assumptions<\/a>.<\/p>\n\n<p>He adds;<\/p>\n\n<blockquote>\nIf we think of the main point of a schema language as defining the language for exchanging information, it seems that RDF\/OWL is a easier to use for extensibility and versioning. Which might be no surprise given the design centres. But given the inability to control the schemas in all the right facets &#8211; such as mandatory extensions &#8211; it doesn&#8217;t fully solve the problems of large scale distributed system extensibility and versioning. More work to be done&#8230;.\n<\/blockquote>\n\n<p>&#8230;which is true, I think there is more work to be done (though I\nalso think what&#8217;s done is a decent 80-90% solution, just as HTTP is\ndespite not having mandatory extensions).  More on mandatory extensions\nand RDF later though; I&#8217;ve given this subject a lot of thought (and code)\nover the past couple of years.<\/p>\n\n<p>P.S. I think it&#8217;s really interesting that Web services proponents\nare discovering the virtues of the Semantic Web <em>before<\/em> they\nreally appreciate all the Web itself has to offer.  I <em>totally<\/em>\ndidn&#8217;t see that coming!  Coincidentally, check out\n<a href=\"http:\/\/www.w3.org\/mid\/20040909124041.7D9E618000EC@mwinf0809.wanadoo.fr\">this message<\/a>\n(lists.w3.org is having issues right now, stay tuned&#8230;) where an\n<a href=\"http:\/\/www.daml.org\/services\/owl-s\/\">OWL-S<\/a>\nuser realizes some of the problems with the Web services model.<\/p>","protected":false},"excerpt":{"rendered":"Kudos to Dave for pulling up his socks and discovering what Semantic Web technologies have to offer first hand &#8211; you know, all that wonderful extensible goodness I&#8217;ve been going on about after discovering it for myself. He talks about a perceived problem here &#8230; In order to prevent an area code, I need to [&hellip;]","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[40],"class_list":["post-451","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-xml"],"_links":{"self":[{"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/posts\/451","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/comments?post=451"}],"version-history":[{"count":0,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/posts\/451\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/media?parent=451"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/categories?post=451"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.markbaker.ca\/blog\/wp-json\/wp\/v2\/tags?post=451"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}