http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/
Kingsley Idehen's Blog Data Space
I have seen the future and it's full of Linked Data! :-)
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-11-21T11:18:24Z
Virtuoso Universal Server 05.12.3041
http://www.openlinksw.com/weblog/public/images/vbloglogo.gif
5 Very Important Things to Note about HTTP based Linked Data
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1591
2009-11-19T19:49:09Z
<ol> <li> It isn't <a href="http://dbpedia.org/resource/World_Wide_Web" id="link-id115dfd68">World Wide Web</a> Specific (HTTP != World Wide Web)</li> <li> It isn't Open <a href="http://dbpedia.org/resource/Data">Data</a> Specific </li> <li> It isn't about "Free" (Beer or Speech) </li> <li> It isn't about Markup (so don't expect to grok it via "markup first" approach) </li> <li>It's about <a href="http://dbpedia.org/resource/Linked_Data" id="link-id13a6aa98">Hyperdata</a> - the use of HTTP and REST to deliver a powerful platform agnostic mechanism for Data Reference, Access, and Integration.</li> </ol> <p> When trying to understand HTTP based <a href="http://dbpedia.org/resource/Linked_Data" id="link-id18aa1490">Linked Data</a>, especially if you're well versed in DBMS technology use (User, Power User, Architect, Analyst, DBA, or Programmer) think:</p> <ul> <li> Open Database Connectivity (<a href="http://dbpedia.org/resource/Open_Database_Connectivity" id="link-id1428fba0">ODBC</a>) without operating system, data model, or wire-protocol specificity or lock-in potential </li> <li> Java Database Connectivity (<a href="http://dbpedia.org/resource/Java_Database_Connectivity" id="link-id18d3c2a8">JDBC</a>) without programming language specificity </li> <li> <a href="http://dbpedia.org/resource/ADO.NET" id="link-id125725b8">ADO</a>.NET without .NET runtime specificity and .NET bound language specificity </li> <li> OLE-DB without Windows operating system & programming language specificity </li> <li> XMLA without XML format specificity - with Tabular and Multidimensional results formats expressible in a variety of data representation formats. </li> <li>All of the above scoped to the Record rather than Container level, with Generic HTTP scheme URIs associated with each Record, Field, and Field value (optionally) </li> </ul> <p>Remember the need for Data Access & Integration technology is the by product of the following realities:</p> <ol> <li> Human curated data is ultimately dirty, because: <ul> <li>our thick thumbs, inattention, distractions, and general discomfort with typing, make typos prevalent</li> <li>database engines exist for a variety of data models - Graph, Relational, Hierarchical;</li> <li>within databases you have different record container/partition names e.g. Table Names;</li> <li>within a database record container you have records that are really aspects of the same thing (different keys exist in a plethora of operational / line of business systems that expose aspects of the same <a href="http://dbpedia.org/resource/Entity" id="link-id13378338">entity</a> e.g., customer data that spans Accounts, CRM, ERP application databases);</li> <li>different field names (one database has "EMP" while another has "Employee") for the same record</li>.</ul> </li> <li>Units of measurement is driven by locale, the UK office wants to see sales in Pounds Sterling while the French office prefers French Francs</li> <li>All of the above is subject to <a href="http://dbpedia.org/resource/Context_%28language_use%29" id="link-id17e46398">context</a> halos which can be quite granular re. sensitivity e.g. staff travel between locations that alter locales and their roles; basically, profiles matters a lot.</li> </ol> <h3>Related</h3> <ul> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1364" id="link-id128f0fe8">ODBC and WODBC (Web Open Database Connectivity) Comparison</a> </li> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1364" id="link-id1367cd18">Creating, Deploying, and Exploiting Linked Data Presentation</a> </li> <li> <a href="http://www.odata.org/" id="link-id122ab708">Open Data Protocol Project</a> </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-11-20T07:12:34.000004-05:00
5 Game Changing Things about the OpenLink Virtuoso + AWS Cloud Combo
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1590
2009-11-18T19:12:56Z
<p> Here are 5 powerful benefits you can immediately derive from the combination of <a href="http://virtuoso.openlinksw.com" id="link-id17eb8988">Virtuoso</a> and Amazon's AWS services (specifically the EC2 and EBS components):</p> <ol> <li> Acquire your own personal or service specific <a href="http://en.wikipedia.org/wiki/Data_Spaces" id="link-id1423e520">data space</a> in the Cloud. Think DBase, Paradox, FoxPRO, Access of yore, but with the power of <a href="http://dbpedia.org/resource/Oracle_Database" id="link-id136c6290">Oracle</a>, <a href="http://dbpedia.org/resource/IBM_Informix" id="link-id11b269b8">Informix</a>, <a href="http://dbpedia.org/resource/Microsoft_SQL_Server" id="link-id138084b8">Microsoft SQL Server</a> etc.. using a Conceptual, as opposed to solely Logical, model based DBMS (i.e., a Hybrid DBMS Engine for: <a href="http://dbpedia.org/resource/SQL" id="link-id132a7938">SQL</a>, RDF, XML, and Full Text) </li> <li> Ability to share and control access to your resources using innovations like <a href="http://dbpedia.org/resource/Friend_of_a_friend" id="link-id17ee9d28">FOAF</a>+SSL, OpenID, and OAuth, all from one place </li> <li> Construction of personal or organization based FOAF profiles in a matter of minutes; by simply creating a basic DBMS (or <a href="http://dbpedia.org/resource/OpenLink_Data_Spaces" id="link-id14784ae0">ODS</a> application layer) account; and then using this profile to create strong links (references) to all your Data silos (esp. those from the <a href="http://dbpedia.org/resource/World_Wide_Web">Web</a> 2.0 realm) </li> <li> Load data sets from the <a href="http://community.linkeddata.org/dataspace/organization/lod#this" id="link-id17e6ac98">LOD</a> cloud or Sponge existing Web resources (i.e., on the fly data transformation to RDF model based <a href="http://dbpedia.org/resource/Linked_Data" id="link-id17e65d38">Linked Data</a>) and then use the combination to build powerful lookup services that enrich the value of URLs (think: Web addressable reports holding query results) that you publish </li> <li> Bind all of the above to a domain that you own (e.g. a .Name domain) so that you have an attribution-friendly "authority" component for resource URLs and <a href="http://dbpedia.org/resource/Entity" id="link-id118a08d8">Entity</a> URIs published from your Personal Linked Data Space on the Web (or private HTTP network). </li> </ol> <p> In a nutshell, the AWS Cloud infrastructure simplifies the process of generating Federated presence on the <a href="http://dbpedia.org/resource/Internet" id="link-id1380af38">Internet</a> and/or <a href="http://dbpedia.org/resource/World_Wide_Web" id="link-id11633b10">World Wide Web</a>. Remember, centralized networking models always end up creating data silos, in some <a href="http://dbpedia.org/resource/Context_%28language_use%29" id="link-id142006f0">context</a>, ultimately! :-) </p>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-11-19T15:20:03.000002-05:00
Personal and/or Service Specific Linked Data Spaces in the Cloud: DBpedia 3.4
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1589
2009-11-16T18:17:46Z
<p> We have just released an Amazon EC2 based public Snapshot of <a href="http://dbpedia.org/resource/DBpedia" id="link-id18e899b8">DBpedia</a> 3.4. Thus, you can now instantiate a personal and/or service specific variant of the DBpedia 3.4 <a href="http://dbpedia.org/resource/Linked_Data" id="link-id168dec90">Linked Data</a> <a href="http://en.wikipedia.org/wiki/Data_Spaces" id="link-id18911268">Space</a>. Basically, you can replicate what we host, within minutes (as opposed to days). In addition, you no longer need to squabble --on an unpredictable basis with others-- for the infrastructure resources behind DBpedia's public instance, when using the <a href="http://dbpedia.org/resource/SPARQL" id="link-id18d5bd78">SPARQL</a> Endpoint, Faceted Search & Find Services, or HTML Browser Pages etc.</p> <h3>How Does It work?</h3> <ol> <li> <a href="http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtInstallationEC2" id="link-id115932b8">Instantiate a Virtuoso EC2 AMI</a> (paid variety, which is aggressively priced at $49.99 for setup and $19.99 per month thereafter)</li> <li> <a href="http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtAWSDBpedia34S" id="link-id182dc800"> Mount the shared DBpedia 3.4 public snapshot</a> </li> <li> Start Virtuoso Server</li> <li> Start exploiting the DBpedia Linked Data Space.</li> </ol> <h3>What Interfaces are exposed?</h3> <ol> <li> SPARQL Endpoint</li> <li> Linked Data Viewer Pages (as you see in the public DBpedia instance)</li> <li> <a href="http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtFacetBrowserInstallConfig" id="link-id117f6e80">Faceted Search & Find UI and Web Services</a> (REST or SOAP)</li> <li> All the inference rules for <a href="http://umbel.org/about/" id="link-id144b84a8">UMBEL</a>, SUMO, YAGO, <a href="http://dbpedia.org/resource/Cyc" id="link-id16b69da8">OpenCYC</a>, and DBpedia-OWL <a href="http://dbpedia.org/resource/Data">data</a> dictionaries</li> <li>Type Correlations Between DBpedia and Freebase</li> </ol> <p>Enjoy!</p>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-11-16T13:30:20-05:00
Conversation with Jon Udell: Are We There Yet Re. Web++ ?
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1584
2009-09-10T15:03:01Z
<p> Personally, I believe that we've actually reached a watershed moment re. the evolution of the <a href="http://dbpedia.org/resource/World_Wide_Web">Web</a> from a mesh of <a href="http://dbpedia.org/resource/Linked_Data" id="link-id123169a8">Linked Data</a> Containers (Web of Linked Documents) to a mesh of Linked Data Items (entities or real world objects).</p> <p> The journey towards this watershed moment started with the <a href="http://dbpedia.org/resource/Semantic_Web" id="link-id14f69f48">Semantic Web</a> Project, gained focus and pragmatism via the <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id11155f78">Linked Data meme</a>, attained substance & credibility via efforts such as <a href="http://dbpedia.org/resource/DBpedia" id="link-id15857c78">DBpedia</a> and the resulting cloud of <a href="http://www4.wiwiss.fu-berlin.de/bizer/pub/lod-datasets_2009-07-14.html" id="link-id16adf918">Open Linked Data Spaces</a>, and finally arrived at the most important destination of all: broad comprehension and coherence, via <a href="http://dbpedia.org/resource/RDFa" id="link-id1229b960">RDFa</a>. </p> <p> Over the years, I've chronicled the journey above via entries in this particular <a href="http://en.wikipedia.org/wiki/Data_Spaces" id="link-id14f76338">data space</a> (my <a href="http://dbpedia.org/resource/Blog" id="link-idfd32c88">blog</a>) and most recently, via my rapid-fire comments and debates on <a href="http://twitter.com" id="link-id11339e80">Twitter</a> (basically hastag #linkeddata account: <a href="http://twitter.com/kidehen#this" id="link-id115e9af8">kidehen</a>). </p> <p> On a parallel front re. my chronicles, I've periodically had conversations with <a href="http://blog.jonudell.net/about/" id="link-id11829170">Jon Udell</a>, who has always provided a coherent sounding board and reconciliation framework for my world views and open data access vision; naturally, this has a lot to do with his holistic grasp of the big picture issues, associated technical details, and special communication prowess :-) </p> <p> Against this backdrop, I refer you to my <a href="http://itc.conversationsnetwork.org/shows/detail4233.html" id="link-id14ac9c08">most recent podcast conversation with Jon</a>, which is about how the tandem of HTML+RDFa and the <a href="http://www.heppnetz.de/projects/goodrelations/" id="link-id14279be8">GoodRelations vocabulary</a> deliver the critical missing links re. broad comprehension of the Semantic Web vision en route to mass exploitation. </p> <h3>Related</h3> <ul> <li> <a href="http://webbackplane.com/node/57" id="link-id113b5b00">Mark Birbeck Introduces RDFa</a> </li> <li> <a href="http://webbackplane.com/rdfa-handbook" id="link-id11b36ac0">RDFa Handbook</a> </li> <li> <a href="http://www.ebusiness-unibw.org/wiki/GoodRelations#CookBook:_GoodRelations_Recipes_and_Examples" id="link-id1519f458">GoodRelations Usage Examples & Templates</a> </li> <li> <a href="http://blog.jonudell.net/2009/09/09/talking-with-kingsley-idehen-about-mastering-your-own-search-index/" id="link-id11a62ce0">Be the master of your own search index</a> </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-09-10T11:32:07.000001-04:00
The URI, URL, and Linked Data Meme's Generic HTTP URI (Updated)
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1567
2009-08-07T18:34:50Z
<h3>Situation Analysis</h3> <p>As the "<a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id12f96a00">Linked Data" meme</a> has gained momentum you've more than likely been on the receiving end of dialog with Linked Open <a href="http://dbpedia.org/resource/Data">Data</a> community members (myself included) that goes something like this:</p> <blockquote> <cite>"Do you have a <a href="http://dbpedia.org/resource/Uniform_Resource_Identifier" id="link-id139252a0">URI</a>", "Get yourself a URI", "Give <a href="http://myopenlink.net/dataspace/person/kidehen#this" id="link-id140eab68">me</a> a de-referencable URI" etc..</cite> </blockquote> <p>And each time, you respond with a <a href="http://dbpedia.org/resource/Uniform_Resource_Locator" id="link-id112c1860">URL</a> -- which to the best of your <a href="http://dbpedia.org/resource/World_Wide_Web">Web</a> <a href="http://dbpedia.org/resource/Knowledge" id="link-id140b51c0">knowledge</a> is a bona fide URI. But to your utter confusion you are told: Nah! You gave me a Document URI instead of the URI of a real-world thing or object etc..</p> <h3>What's up with that?</h3> <p>Well our everyday use of the Web is an unfortunate conflation of two distinct things, which have Identity: Real World Objects (RWOs) & Address/Location of Documents (<a href="http://dbpedia.org/resource/Information" id="link-id144838b0">Information</a> bearing Resources).</p> <p>The "Linked Data" meme is about enhancing the Web by unobtrusively reintroducing its core essence: the generic HTTP URI, a vital piece of Web Architecture DNA. Basically, its about so realizing the full capabilities of the Web as a platform for Open Data Identification, Definition, Access, Storage, Representation, Presentation, and Integration.</p> <h3>What is a Real World Object?</h3> <p>People, Places, Music, Books, Cars, Ideas, Emotions etc..</p> <h3>What is a URI?</h3> <p>A Uniform Resource Identifier. A global identifier mechanism for network addressable data items. Its sole function is Name oriented Identification.</p> <h4>URI Generic Syntax</h4> <p>The constituent parts of a URI (from <a href="http://www.ietf.org/rfc/rfc2396.txt" id="link-id1180c700">URI Generic Syntax RFC</a>) are depicted below: <img alt="Image" src="http://virtuoso.openlinksw.com/images/generic_uri_syntax_image.png" /> </p> <h3>What is a URL?</h3> <p>A location oriented HTTP scheme based URI. The HTTP scheme introduces a powerful and inherent duality that delivers:</p> <ol> <li> Resource Address/Location Identifier</li> <li> Data Access mechanism for an Information bearing Resource (Document, File etc..) </li> </ol> <p>So far so good!</p> <h3>What is an HTTP based URI?</h3> <p>The kind of URI <a href="http://dbpedia.org/resource/Linked_Data" id="link-id11100a28">Linked Data</a> aficionados mean when they use the term: URI.</p> <p>An HTTP URI is an HTTP scheme based URI. Unlike a URL, this kind of HTTP scheme URI is devoid of any Web Location orientation or specificity. Thus, Its inherent duality provides a more powerful level of abstraction. Hence, you can use this form of URI to assign Names/Identifiers to Real World Objects (RWO). Even better, courtesy of the Identity/Address duality of the HTTP scheme, a single URI can deliver the following:</p> <ol> <li> RWO Identfier/Name</li> <li> RWO Metadata document Locator (courtesy of URL aspect) </li> <li> Negotiable Representation of the Located Document (courtesy of HTTP's content negotiation feature).</li> </ol> <h3>What is Metadata?</h3> <p> Data about Data. Put differently, data that describes other data in a structured manner.</p> <h3>How Do we Model Metadata?</h3> <p>The predominant model for metadata is the <a href="http://dbpedia.org/resource/Entity-attribute-value_model" id="link-id11193d30">Entity</a>-Attribute-Value + Classes & Relationships model (<a href="http://dbpedia.org/resource/Entity-attribute-value_model" id="link-id11725710">EAV</a>/CR). A model that's been with us since the inception of modern computing (long before the Web). </p> <h3>What about RDF?</h3> <p>The Resource Description Framework (RDF) is a framework for describing Web addressable resources. In a nutshell, its a framework for adding Metadata bearing Information Resources to the current Web. Its comprised of:</p> <ol> <li> Entity-Attribute-Value (aka. Subject-Predictate-Object) plus Classes & Relationships (<a href="http://dbpedia.org/resource/Data_dictionary" id="link-id138df0f8">Data Dictionaries</a> e.g., <a href="http://dbpedia.org/resource/Web_Ontology_Language" id="link-id116bf590">OWL</a>) metadata model</li> <li> A plethora of instance data representation formats that include: <a href="http://dbpedia.org/resource/RDFa" id="link-id13360b90">RDFa</a> (when doing so within (X)HTML docs), Turtle, N3, TriX, RDF/XML etc. </li> </ol> <h3>What's the Problem Today?</h3> <p>The ubiquitous use of the Web is primarily focused on a Linked Mesh of Information bearing Documents. URLs rather than generic HTTP URIs are the prime mechanism for Web tapestry; basically, we use URLs to conduct Information -- which is inherently subjective -- instead of using HTTP URIs to conduct "Raw Data" -- which is inherently objective. </p> <blockquote> <strong>Note:</strong> Information is "data in <a href="http://dbpedia.org/resource/Context_%28language_use%29" id="link-id1395ca50">context</a>", it isn't the same thing as "Raw Data". Thus, if we can link to Information via the Web, why shouldn't we be able to do the same for "Raw Data"?</blockquote> <h3>How Does the Link Data <a href="http://dbpedia.org/resource/Meme" id="link-id1160ab70">meme</a> solve the problem?</h3> <p>The meme simply provides a set of guidelines (best practices) for producing Web architecture friendly metadata. Meaning: when producing EAV/CR model based metadata, endow Subjects, their Attributes, and Attribute Values (optionally) with HTTP URIs. By doing so, a new level of Link Abstraction on the Web is possible i.e., "Data Item to Data Item" level links (aka <a href="http://dbpedia.org/resource/Linked_Data" id="link-id137a78a0">hyperdata</a> links). Even better, when you de-reference a RWO hyperdata link you end up with a negotiated representations of its metadata.</p> <h3>Conclusion</h3> <p>Linked Data is ultimately about an HTTP URI for each item in the <a href="http://dbpedia.org/resource/Data_hierarchy" id="link-id1393c3e0">Data Organization Hierarchy</a> :-)</p> <h3>Related</h3> <ol> <li> <a href="http://www.nabble.com/Review-of-new-HTTPbis-text-for-303-See-Other-to24035004.html#a24774368" id="link-id10fcaba8">History of how "Resource" became part of URI</a> - historic account by <a href="http://www.w3.org/People/Berners-Lee/card#i" id="link-id1172b128">TimBL</a> </li> <li> <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id1338cbd0">Linked Data Design Issues Document</a> - <a href="http://www.w3.org/People/Berners-Lee/card#i" id="link-id13536ad8">TimBL</a>'s initial Linked Data Guide</li> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1561" id="link-id116c1af8">Linked Data Rules Simplified</a> - My attempt at simplifying the Linked Data Meme without <a href="http://dbpedia.org/resource/SPARQL" id="link-id116c3b40">SPARQL</a> & RDF distraction</li> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1547" id="link-id135dd1b8">Linked Data & Identity</a> - another related post</li> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1565" id="link-id134afc50">The Linked Data Meme's Value Proposition</a> </li> <li> <a href="http://delicious.com/kidehen/identifier_scheme" id="link-id14cc7e18">My Del.icio.us hosted Bookmark Data Space for Identity Schemes</a> </li> <li> <a href="http://www.ted.com/talks/tim_berners_lee_on_the_next_web.html" id="link-id115a3748">TimBL's Ted Talk re. "Raw Linked Data"</a>.</li> </ol>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-10-07T08:02:34-04:00
Why Do We Put Stuff On The Web, Really?
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1566
2009-07-24T15:54:26Z
<p>As espoused by the Ubuntu philosophy, no Human is an Island. Thus, although the objects of our sociality are vast and varied; that said, the basic foundation still centers on the pursuit and/or delivery of products and services.</p> <p>Today, the we put stuff on the <a href="http://dbpedia.org/resource/World_Wide_Web">Web</a> because we want it do be discovered as part of a "sharing act". Likewise, we make regular use of Search Engine Services because we want to "Find" stuff in a productive manner.</p> <p>Putting, the above in <a href="http://dbpedia.org/resource/Context_%28language_use%29" id="link-id1340d970">context</a>, you don't need to be Einstein to figure out that to date the Web hasn't enabled vendors to describe their products and services clearly. Likewise, it hasn't enabled us to describe what we want, when we want it, and how much we are willing to pay etc. Basically, the SDQ of Web Content is excruciatingly low!</p> <p> The <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id1357e068">Linked Data meme</a> is about using the essence of the Web -- HTTP URIs -- as the mechanism for conducting <a href="http://dbpedia.org/resource/Data">data</a> across the Web that unambiguously unveils basic things like:</p> <ol> <li> Using a personal profile to describe exactly who I am, my interests, favorite things, what I want (wishlist), what I have to offer (offerlist) etc.</li> <li> Using an company profile to describe my entire product catalog, inventory levels, store locations, distributor and reseller networks, feature specs, price specs, deal terms and duration, and even opening and closing hours.</li> </ol> <h3>Conclusions</h3> <p>A Web of <a href="http://dbpedia.org/resource/Linked_Data" id="link-id124f7778">Linked Data</a> enables a complete redefinition of eCommerce, and that's just for starters :-)</p> <h3>Related</h3> <ul> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1442" id="link-id112b62c0">Post Introducing SDQ</a> </li> <li> <a href="http://www.seangolliher.com/2009/linked-data/serendipitous-discovery-quotient-sdq-the-future-of-seo-or-an-abstract-concept/" id="link-id110cf500">Serendipitous Discovery Quotient (SDQ): The Future of SEO? Or an Abstract Concept?</a> </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-07-24T21:00:21-04:00
Exploring the Value Proposition of Linked Data
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1565
2009-07-24T00:17:19Z
<h3>What is <a href="http://dbpedia.org/resource/Linked_Data" id="link-id138c9aa8">Linked Data</a>?</h3> <p> The primary topic of a <a href="http://dbpedia.org/resource/Meme" id="link-id12f86100">meme</a> penned by <a href="http://www.w3.org/People/Berners-Lee/card#i" id="link-id115b4c98">TimBL</a> in the form of a <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id1333f300">Design Issues Doc</a> (note: this is how TimBL has shared his thoughts since the <a href="http://www.w3.org/DesignIssues/" id="link-id1128a1d0">Beginning of the Web</a>). </p> <p> There are a number of dimensions to the meme, but its primary purpose is the reintroduction of the HTTP <a href="http://dbpedia.org/resource/Uniform_Resource_Identifier" id="link-id13c43cb8">URI</a> -- a vital component of the Web's core architecture. </p> <h3> What's Special about HTTP URIs?</h3> <p> They possess an intrinsic duality that combines persistent and unambiguous <a href="http://dbpedia.org/resource/Data">Data</a> Identity with platform & representation format independent Data Access. Thus, you can use a string of characters that look like a contemporary Web <a href="http://dbpedia.org/resource/Uniform_Resource_Locator" id="link-id119cd8a0">URL</a> to unambiguously achieve the following: </p> <ol> <li>Identity or Name Anything of Interest</li> <li>Describe Anything of Interest by associating the Description Subject's Identity with a constellation of Attribute and Value pairs (technically: an <a href="http://dbpedia.org/resource/Entity-attribute-value_model" id="link-id1133e8a8">Entity</a>-Attribute-Value or Subject-Predicate-Object graph)</li> <li>Make the Description of Named Things of Interest discoverable on the Web by implicitly binding the aforementioned to Documents that hold their descriptions (technically: metadata documents or <a href="http://dbpedia.org/resource/Information" id="link-id1391da40">information</a> resources)</li> </ol> <h3>What's the basic value proposition of the <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id113bb690">Linked Data meme</a>?</h3> <p>Enabling more productive use of the Web by users and developers alike. All of which is achieved by tweaking the Web's Hyperlinking feature such that it now includes Hypertext and <a href="http://dbpedia.org/resource/Linked_Data" id="link-id1337a3f0">Hyperdata</a> as link types.</p> <p>Note: Hyperdata Linking is simply what an HTTP URI facilitates.</p> <p>Examples problems solved by injecting Linked Data into the Web:</p> <ol> <li>Federated Identity by enabling Individuals to unambiguously Identify themselves (Profiles++) courtesy of existing <a href="http://dbpedia.org/resource/Internet" id="link-id13926e28">Internet</a> and Web protocols (e.g., <a href="http://dbpedia.org/resource/Friend_of_a_friend" id="link-id13646ec8">FOAF</a>+SSL's WebIDs which combine Personal Identity with X.509 certificates and HTTPs based client side certification)</li> <li>Security and Privacy challenge alleviation by delivering a mechanism for policy based data access that feeds off federated individual identity and social network (graph) traversal</li> <li>Spam Busting via the above</li>. <li> Increasing the Serendipitous Discovery Quotient (SDQ) of Web accessible resources by embedding Rich Metadata into (X)HTML Documents e.g., structured descriptions of your "WishLists" and "OfferLists" via a common set of terms offered by vocabularies such as <a href="http://www.heppnetz.de/projects/goodrelations/" id="link-id1199b4d0">GoodRelations</a> and <a href="http://dbpedia.org/resource/SIOC" id="link-id1334cfb0">SIOC</a> </li> <li>Coherent integration of disparate data across the Web and/or within the Enterprise via "Data Meshing" rather than "Data Mashing"</li> <li>Moving beyond imprecise statistically driven "Keyword Search" (e.g. Page Rank) to "Precision Find" driven by typed link based <a href="http://dbpedia.org/resource/Entity" id="link-id135f6fe8">Entity</a> Rank plus Entity Type and Entity Property filters.</li> </ol> <h3>Conclusion</h3> <p>If all of the above still falls into the technical mumbo-jumbo realm, then simply consider Linked Data as delivering Open Data Access in granular form to Web accessible data -- that goes beyond data containers (documents or files).</p> <p>The value proposition of Linked Data is inextricably linked to the value proposition of the <a href="http://dbpedia.org/resource/World_Wide_Web" id="link-id1356f5c0">World Wide Web</a>. This is true, because the Linked Data meme is ultimately about an enhancement of the current Web; achieved by reintroducing its architectural essence -- in new <a href="http://dbpedia.org/resource/Context_%28language_use%29" id="link-id11300828">context</a> -- via a new level of link abstraction, courtesy of the Identity and Access duality of HTTP URIs.</p> <p>As a result of Linked Data, you can now have Links on the Web for a Person, Document, Music, Consumer Electronics, Products & Services, Business Opening & Closing Hours, Personal "WishLists" and "OfferList", an Idea, etc.. in addition to links for Properties (Attributes & Values) of the aforementioned. Ultimately, all of these links will be indexed in a myriad of ways providing the substrate for the next major period of Internet & Web driven innovation, within our larger human-ingenuity driven innovation continuum.</p> <h3>Related</h3> <ul> <li> <a href="http://www.ebusiness-unibw.org/wiki/GoodRelations#Recipes_and_Examples" id="link-id11386648">Recipes for Describing Your Business and its Offerings using the GoodRelations Vocabulary / Schema</a> </li> <li> <a href="http://slidesix.com/view/SolvingRealProblemsUsingLinkedData" id="link-id13658ee0">Solving Real Problems with RDF based Linked Data</a> </li> <li> <a href="http://www.openlinksw.com/weblog/public/search.vspx?blogid=127&q=linked%20data&type=text&output=html" id="link-id1175a650">Other Linked Data Posts from this Blog oriented Linked Data Space</a> (goes back a few years!)</li> <li>Various practical <a href="http://delicious.com/kidehen/linked_data_demo" id="link-id13390cf8">Linked Data demo links from my Del.icio.us Bookmark oriented Data Space</a> </li> <li> <a href="http://myopenlink.net/dataspace/person/kidehen#this" id="link-id132cda80">My personal WebID</a> which is conduit to a Linked Data mesh covering vast variety of things I've opted to share with others via the Web (best viewed using a Linked Data aware User Agent like ODE).</li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-07-24T08:20:01-04:00
Important Things to Note about the World Wide Web
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1564
2009-07-23T13:27:11Z
<p>Based on the prevalence of confusion re. the <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id135eee50">Linked Data meme</a>, here are a few important points to remember about the <a href="http://dbpedia.org/resource/World_Wide_Web" id="link-id1118b210">World Wide Web</a>.</p> <ol> <li>Its an HTTP based Network Cluster within the <a href="http://dbpedia.org/resource/Internet" id="link-id1332a6e8">Internet</a> (remember: Networks are about meshes of Nodes connected by Links)</li> <li>Its underlying <a href="http://dbpedia.org/resource/Data">data</a> model is that of a Network (we've had Network Data models for eons. <a href="http://dbpedia.org/resource/Entity-attribute-value_model" id="link-id13350310">EAV</a>/CR is an example)</li> <li>Links are facilitated via URIs</li> <li>Until recently the granularity of Networking on the <a href="http://dbpedia.org/resource/World_Wide_Web">Web</a> was scoped to Data Containers (documents) (due to prevalence of <a href="http://dbpedia.org/resource/Uniform_Resource_Locator" id="link-id12f7c078">URL</a> style links</li> <li>The Linked Data meme adds Data Item (Datum) level granularity to World Wide Web networking via HTTP URIs</li> <li>Data Items become Web Reference-able when you Identify/Name them using HTTP based URIs</li> <li>An HTTP <a href="http://dbpedia.org/resource/Uniform_Resource_Identifier" id="link-id135ffdb8">URI</a> implicitly binds a Web Reference-able Data Item (<a href="http://dbpedia.org/resource/Entity" id="link-id113afb60">Entity</a>, Datum, Data Object, Resource) to its Web Accessible Metadata</li> <li>Web Accessible Metadata resides within Data Containers (documents or <a href="http://dbpedia.org/resource/Information" id="link-id11402318">information</a> resources)</li> <li>The representation of a Web Accessible Metadata container is negotiable</li> <li>I am able to write and dispatch this <a href="http://dbpedia.org/resource/Blog" id="link-id0x770cbd0">blog</a> post courtesy of the Web features listed above</li> <li>You are able to explore the many dimensions to data exposed by this blog should you decide to explore the <a href="http://dbpedia.org/resource/Linked_Data" id="link-id0x7acd540">Linked Data</a> mesh exposed by this post's HTTP URI (via its permalink permalink)</li> </ol> <p>The HTTP URI is the secret sauce of the Web that is powerfully and unobtrusively reintroduced via the Linked Data meme (classic back to the future act). This powerful sauce possess a unique power courtesy of its inherent duality i.e., how it uniquely combines Data Item Identity (think keys in traditional DBMS parlance) with Data Access (e.g. access to negotiable representations of associated metadata).</p> <p>As you can see, I've made no mention of RDF or <a href="http://dbpedia.org/resource/SPARQL" id="link-id1183bd48">SPARQL</a>, and I can still articulate the inherent value of the "<a href="http://dbpedia.org/resource/Linked_Data" id="link-id132e7058">Linked Data</a>" dimension that the "Linked Data" meme adds to the World Wide Web.</p> <p>As per usual this post is a live demonstration of Linked Data (dog-food style) :-)</p> <h3>Related</h3> <ul> <li> <a href="http://www.semanticsincorporated.com/2009/07/if-linked-data-is-a-brand-it-has-big-problems-to-address.html" id="link-id1171d4e8">Greg Boutin's post about Linked Data Brand Management</a> </li> <li> <a href="http://iandavis.com/blog/2009/07/the-linked-data-brand" id="link-id12db0880">Ian Davis' "Linked Data Brand" post</a> </li> <li> <a href="http://cloudofdata.com/2009/07/does-linked-data-need-rdf/" id="link-id13537230">Paul Miller's "Does Linked Data need RDF" post</a> </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-07-23T10:33:58-04:00
Linked Data Rules Simplified
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1561
2009-06-26T14:49:03Z
<p>As a compliment to the most recent <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id11a6a9b8">Linked Data Design Issues</a> note by <a href="http://www.w3.org/People/Berners-Lee/card#i" id="link-id114c1ae8">TimBL</a>, I would like to add this subtle tweak to the enumerated rules:</p> <ol> <li> Identify or Name things using HTTP URIs </li> <li> Describe things using the RDF metadata model </li> <li> Increase link <a href="http://dbpedia.org/resource/Data">data</a> mesh density on the <a href="http://dbpedia.org/resource/World_Wide_Web">Web</a> by linking (referring) to things in other data spaces using their HTTP URIs. </li> </ol> <p> If you perform the steps above, on any HTTP network (e.g. <a href="http://dbpedia.org/resource/World_Wide_Web" id="link-iddbef1f0">World Wide Web</a>), you implicitly bind the Names/Identifiers of things to negotiable representations of their metadata (description) bearing documents. </p> <p> Also note, you can create and deploy the resulting RDF metadata using any of the following approaches:</p> <ol> <li> <a href="http://dbpedia.org/resource/RDFa" id="link-id14442c00">RDFa</a> within (X)HTML documents</li> <li> N3, Turtle, TriX, RDF/XML etc. based documents </li> <li>Programmatically generated variants of 1&2.</li> </ol> <h3>Related</h3> <ul> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1546" id="link-id1181ebf0">What is the Linked Data meme about?</a> </li> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1543" id="link-id13039a98">Simple Explanation of RDF and Linked Data Dynamics</a> </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-06-26T23:18:24.000003-04:00
BBC Linked Data Meshup In 3 Steps
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1560
2009-06-12T18:09:08Z
<h3>Situation Analysis:</h3> <p>Dr. Dre is one of the artists in the <a href="http://dbpedia.org/resource/Linked_Data" id="link-id1117a230">Linked Data</a> <a href="http://en.wikipedia.org/wiki/Data_Spaces" id="link-id10ff0fc0">Space</a> we host for the <a href="http://dbpedia.org/resource/BBC" id="link-id13cdba70">BBC</a>. He is also referenced in music oriented <a href="http://dbpedia.org/resource/Data">data</a> spaces such as <a href="http://dbpedia.org/resource/DBpedia" id="link-id119688a0">DBpedia</a>, <a href="http://musicbrainz.org/" id="link-id146f7d00">MusicBrainz</a> and <a href="http://last.FM" id="link-id15f50698">Last.FM</a> (to name a few). </p> <h3>Challenge:</h3> <p>How do I obtain a holistic view of the <a href="http://dbpedia.org/resource/Entity" id="link-id147a1490">entity</a> "Dr. Dre" across the BBC, MusicBrainz, and Last.FM data spaces? We know the BBC published Linked Data, but what about Last.FM and MusicBrainz? Both of these data spaces only expose XML or JSON data via REST APIs?</p> <h3>Solution:</h3> Simple 3 step Linked Data Meshup courtesy of <a href="http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtSponger" id="link-id147faf78">Virtuoso's in-built RDFizer Middleware</a> "the Sponger" (think <a href="http://dbpedia.org/resource/Open_Database_Connectivity" id="link-id115ecea0">ODBC</a> Driver Manager for the Linked Data <a href="http://dbpedia.org/resource/Giant_Global_Graph" id="link-id11806418">Web</a>) and its numerous Cartridges (think ODBC Drivers for the Linked Data Web). <h3>Steps:</h3> <ol> <li> Go to Last.FM and search using pattern: Dr. Dre (you will end up with this <a href="http://dbpedia.org/resource/Uniform_Resource_Locator" id="link-id11778f10">URL</a>: http://www.last.fm/music/Dr.+Dre)</li> <li> Go to the Virtuoso powered <a href="http://bbc.openlinksw.com" id="link-id14f40338">BBC Linked Data Space home page</a> and enter: http://bbc.openlinksw.com/about/html/http://www.last.fm/music/Dr.+Dre</li> <li> Go to the BBC Linked Data Space home page and type full text pattern (using default tab): Dr. Dre, then view <a href="http://bbc.openlinksw.com/fct/rdfdesc/usage.vsp?g=http%3A%2F%2Fwww.bbc.co.uk%2Fmusic%2Fartists%2F5f6ab597-f57a-40da-be9e-adad48708203%23artist&tp=4&sid=519&urilookup=&orig_refr=http://bbc.openlinksw.com/describe/?url=http://www.bbc.co.uk/music/artists/5f6ab597-f57a-40da-be9e-adad48708203" id="link-id119ac658">Dr. Dre's metadata via the Statistics Link</a>. </li> </ol> <h3>What Happened?</h3> <p>The following took place:</p> <ol> <li> Virtuoso <a href="http://virtuoso.openlinksw.com/Whitepapers/html/VirtSpongerWhitePaper.html" id="link-id11a46fd8">Sponger</a> sent an HTTP GET to Last.FM</li> <li> Distilled the "Artist" entity "Dr. Dre" from the page, and made a <a href="http://dbpedia.org/resource/Resource_Description_Framework" id="link-id1297cc68">Linked Data graph</a> </li> <li> Inverse Functional Property and sameAs reasoning handled the Meshup (augmented graph from a conjunctive query processing pipeline)</li> <li>Links for "Dr. Dre" across <a href="http://bbc.openlinksw.com/describe/?url=http%3A%2F%2Fdbpedia.org%2Fresource%2FDr._Dre" id="link-id119e63e8">BBC (sameAs), Last.FM (seeAlso), via DBpedia URI</a>.</li> </ol> <p>The <a href="http://bbc.openlinksw.com/about/rdf/http/www.last.fm/music/Dr.+Dre#this" id="link-id111f6130">new enhanced URI for Dr. Dre</a> now provides a rich holistic view of the aforementioned "Artist" entity. This URI is usable anywhere on the Web for Linked Data Conduction :-)</p> <h3>Related (as in NearBy)</h3> <ul> <li> <a href="http://blogs.talis.com/n2/archives/617" id="link-idf3e0898">Augmenting Last.fm Data with BBC data on the Talis Platform</a> </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-06-12T16:38:34.000046-04:00
Understanding the BBC's Virtuoso Powered Linked Data Space
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1559
2009-06-11T21:59:31Z
<p> The <a href="http://welcomebackstage.com/2009/06/bbc-backstage-sparql-endpoint/" id="link-id12969860">BBC's recently announced Linked Data space for Programmes and Music data</a>, joins a growing list of immediately useful "<a href="http://virtuoso.openlinksw.com" id="link-id110918f8">Virtuoso</a> Powered" linked data spaces, driving the burgeoning Web of Linked Data. Others include: <a href="http://dbpedia.org/resource/DBpedia" id="link-id12c0e720">DBpedia</a>, <a href="http://www.bio2rdf.org/" id="link-id14ee63a8">Bio2RDF</a>, NeuroCommons etc (the <a href="http://www4.wiwiss.fu-berlin.de/bizer/pub/lod-datasets_2009-03-27.html" id="link-id129a8588">click friendly version of the LOD-Cloud</a> diagram reveals a snapshot of other Virtuoso driven linked data spaces).</p> <h3>Why is it important?</h3> <p> As a leading media organization, the BBC's use of Linked Data provides a clear beacon to other media players re. the imminence of a serious Linked Data induced sector inflection. In a nutshell, every Web Site has to evolve into a Linked Data Space: a location on the Web that provides granular access to discrete data items in line with the core principles of the <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id11a14710">Linked Data meme</a>.</p> <p> Remember, the essence of the Linked Data meme is simply this: you reference data items and access their metadata, in variety of formats via a single HTTP based <a href="http://dbpedia.org/resource/Uniform_Resource_Identifier" id="link-id1136b1c8">URI</a>. This approach to Web data publishing is compatible with any HTTP aware user agent (e.g., your Web Browser or tools & applications that provide abstracted access to HTTP).</p> <h3>How Do I use it?</h3> <p>There a number of very powerful things available to end-users and developers alike.</p> <h4>End-Users:</h4> <p> The most powerful feature of our variant of the BBC's Linked Data Space is the exposure of Faceted Find (think Search++ and beyond). Thus, you can go the the <a href="http://bbc.openlinksw.com" id="link-id12a32770">home page of the service</a> and commence data discovery and exploration via any of the following interfaces:</p> <ul> <li> <a href="http://dbpedia.org/resource/Full_text_search" id="link-id1179d618">Full Text Search</a> Tab -- type in a full text pattern and then experience <a href="http://bbc.openlinksw.com/facet_doc.html" id="link-id12c6dab0">Linked Data Entity Ranking as opposed to Page Ranking</a> </li> <li>URI Lookup (By Label) Tab -- type in part of a URI and let the system auto-complete by looking up Entity Labels</li> <li>URI Lookup (Raw String Pattern) Tab -- type in part of a URI and let the system auto-complete by looking up the raw URI</li> <li> <a href="http://bbc.openlinksw.com/ode/" id="link-id114b53c8">OpenLink Data Explorer Service</a> -- "deceptively simple" Linked Data explorer and Data Mesher (simply type in a URI or Text pattern, then view the data via a myriad of entity type specific viewer tabs).</li> </ul> <p>Once you are comfortable with at least one of the items above, you can exploit the system further by performing any of the following:</p> <ul> <li> <a href="http://bbc.openlinksw.com/page/void/Dataset" id="link-id117616c0">Explore the Linked Data Space via Data Dictionary</a> -- click on a Named Data Set URI and then <a href="http://bbc.openlinksw.com/describe/?url=http%3A%2F%2Fpurl.org%2Fontology%2Fpo%2FEpisode" id="link-id11664778">explore Class instances</a> (rdf:type property values) </li> <li> <a href="http://bbc.openlinksw.com/fct/rdfdesc/usage.vsp?g=http%3A%2F%2Fwww.bbc.co.uk%2Fmusic%2Fartists%2F5f6ab597-f57a-40da-be9e-adad48708203%23artist&tp=4&sid=519&urilookup=&orig_refr=http://bbc.openlinksw.com/describe/?url=http://www.bbc.co.uk/music/artists/5f6ab597-f57a-40da-be9e-adad48708203" id="link-id128a1aa8">Explore Entity Metadata</a> -- currently labeled "Statistics" but really is "Metadata" that describes data about an Entity (how you discern identifier co-reference, indirect identifiers, references from other data sets, and provenance/source graphs).</li> </ul> <h4> <a href="http://dbpedia.org/resource/Information" id="link-id1136cc60">Information</a> Architects & Developers</h4> <ul> <li>Bare bones <a href="http://dbpedia.org/resource/SPARQL" id="link-id13c15448">SPARQL</a> Endpoint -- usable by SPARQL aware user agents </li> <li> <a href="http://bbc.openlinksw.com/sparql_demo/" id="link-id114ed7f0">SPARQL Query Tool</a> -- type in SPARQL and interact with result pages that enable URI navigation (de-referencing)</li> <li> <a href="http://bbc.openlinksw.com/isparql" id="link-id12a25b38">iSPARQL Query By Example</a> -- paint your SPARQL Query and Learn <a href="http://wikis.openlinksw.com/dataspace/owiki/wiki/OATWikiWeb/InteractiveSparqlQueryBuilder" id="link-id13c0c578">SPARQL by Example</a> (just take defaults and then click "OK" to get in)</li> <li> <a href="http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VirtFacetBrowserInstallConfig" id="link-id15001fe0">Virtuoso Facets API</a> - REST API for Faceted Browsing & Navigation across Linked Data Set Dimensions.</li> </ul> <h3>Disambiguated Search (aka. Search++ or Find)</h3> <p> In line with the time-tested "embrace and extend" pattern, we provide Full Text search capability, but unlike Google, Yahoo!, Bing and other search engines, we don't use use "Page Rank" algorithm to sort results; instead, we use an "Entity Rank" algorithm since we are dealing with an RDF based Graph model DBMS where links exist between entities across instance data and data dictionary (vocabularies, schemas, ontologies) boundaries. In addition, when you get results (by clicking "show values" or "show values with distinct counts") that list entities associated with a full text search pattern, we take a quantum leap beyond search engines by allowing you to use "Entity Type" and/or "Entity Properties" (all of these have HTTP URIs too) to set your own <a href="http://dbpedia.org/resource/Context_%28language_use%29" id="link-id13c15c30">context</a> for what you seek.</p> <p>Much more to come in the form of <a href="http://bbc.openlinksw.com/fct/facet.vsp?cmd=featured&sid=423&no_qry=1" id="link-id128a0fd0">BBC specific demo queries</a> and tutorials :-)</p> <h3>Related</h3> <ul> <li> Live <a href="http://lod.openlinksw.com" id="link-id14eb3010">LOD Cloud Cache</a> instance that combines BBC data with other data sets from the LOD Cloud (in a single Virtuoso RDF DBMS hosting 5 Billion+ triples & counting) </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-06-26T23:15:13.000001-04:00
Library of Congress & Reasonable Linked Data
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1556
2009-05-05T17:53:24Z
<p> While exploring the <a href="http://id.loc.gov/authorities/" id="link-id1488cca8">Subject Headings Linked Data Space</a> (LCSH) recently unveiled by the <a href="http://id.loc.gov/" id="link-id1672ad10">Library of Congress</a>, I noticed that the <a href="http://dbpedia.org/resource/Uniform_Resource_Identifier" id="link-id158fef78">URI</a> for the subject heading: <a href="http://id.loc.gov/authorities/sh95000541#concept" id="link-id14c8d3e8">World Wide Web</a>, exposes an "owl:sameAs" link to resource URI: "info:lc/authorities/sh95000541" -- in fact, a URI.URN that isn't HTTP protocol scheme based.</p> <p> The observations above triggered a <a href="http://search.twitter.com/search?q=&ands=&phrase=&ors=&nots=&tag=linkeddata&lang=all&from=kidehen&to=edsu&ref=&near=&within=15&units=mi&since=2009-05-01&until=2009-05-05&rpp=10" id="link-id14e21ba0">discussion thread on Twitter</a> that involved: <a href="http://twitter.com/edsu" id="link-ide411808">@edsu</a>, <a href="http://twitter.com/iand" id="link-id11915ed0">@iand</a>, and <a href="http://twitter.com/kidehen" id="link-id1519c028">moi</a>. Naturally, it morphed into a live demonstration of: human vs machine, interpretation of claims expressed in the RDF graph.</p> <h3>What makes this whole thing interesting?</h3> <p>It showcases (in Man vs Machine style) the issue of unambiguously discerning the meaning of the owl:sameAs claim expressed in the LCSH <a href="http://dbpedia.org/resource/Resource_Description_Framework" id="link-id17004728">Linked Data Space</a>.</p> <h4>Perspectives & Potential Confusion</h4> <p> From the Linked Data perspective, it may spook a few people to see owl:sameAs values such as: "info:lc/authorities/sh95000541", that cannot be de-referenced using HTTP. </p> <p> It may confuse a few people or user agents that see URI de-referencing as not necessarily HTTP specific, thereby attempting to de-reference the URI.URN on the assumption that it's associated with a "<a href="http://www.handle.net/overviews/overview.html" id="link-id155517a8">handle system</a>", for instance.</p> <p> It may even confuse RDFizer / RDFization middleware that use owl:sameAs as a <a href="http://dbpedia.org/resource/Data">data</a> provider attribution mechanism via hint/nudge URI values derived from original content / data URI.URLs that de-reference to nothing e.g., an original resource URI.<a href="http://dbpedia.org/resource/Uniform_Resource_Locator" id="link-id119e0d80">URL</a> plus "#this" which produces URI.URN-URL -- think of this pattern as "owl:shameAs" in a sense :-)</p> <h3> Unambiguously Discerning Meaning</h3> <p> Simply bring OWL reasoning (inference rules and reasoners) into the mix, thereby negating human dialogue about interpretation which ultimately unveils a mesh of orthogonal view points. Remember, OWL is all about infrastructure that ultimately enables you to express yourself clearly i.e., say what you mean, and mean what you say. </p> <h3>Path to Clarity (using <a href="http://virtuoso.openlinksw.com" id="link-id1537aa68">Virtuoso</a>, its in-built Sponger Middleware, and Inference Engine):</h3> <ol> <li>GET the data into the Virtuoso Quad store -- what the sponger does via its <a href="http://linkeddata.uriburner.com/about/html/http://id.loc.gov/authorities/sh95000541#concept" id="link-id1669fa40">URIBurner Service</a> (while following designated predicates such as owl:sameAs in case they point to other mesh-able data sources)</li> <li>Query the data in Quad Store with "owl:sameAs" inference rules enabled</li> <li>Repeat the last step with the inference rules excluded.</li> </ol> <h4>Actual <a href="http://dbpedia.org/resource/SPARQL" id="link-id17374110">SPARQL</a> Queries:</h4> <ul> <li> <a href="http://demo.openlinksw.com/DAV/home/demo/Public/Queries/DataWeb/lcsh_www_subject_heading.isparql" id="link-id16c986d0">SPARQL Query against the HTTP based Subject Heading URI for WWW</a> </li> <li> <a href="http://demo.openlinksw.com/DAV/home/demo/Public/Queries/DataWeb/lcsh_www_subject_heading_sameAs_inference_on.isparql" id="link-id16d4fea0">SPARQL Query (with reasoning via inference rule for owl:sameAs)</a> against the URN based Subject Heading URI for WWW</li> <li> <a href="http://demo.openlinksw.com/DAV/home/demo/Public/Queries/DataWeb/lcsh_www_subject_heading_no_sameAs_inference_on.isparql" id="link-id11bad768">SPARQL Query (*without* reasoning via inference rule for owl:sameAs)</a> against the URN based Subject Heading URI for WWW</li> </ul> <h4>Observations:</h4> <p> The <a href="http://dbpedia.org/resource/SPARQL" id="link-ide6acf68">SPARQL</a> queries against the Graph generated and automatically populated by the Sponger reveal -- without human intervention-- that: "info:lc/authorities/sh95000541", is just an alternative name for < xmlns="http" id.loc.gov="id.loc.gov" authorities="authorities" sh95000541="sh95000541" concept="concept">, and that the graph produced by LCSH is self-describing enough for an OWL reasoner to figure this all out courtesy of the <a href="http://linkeddata.uriburner.com/about/html/http://www.w3.org/2002/07/owl%23sameAs" id="link-id13e364b0">owl:sameAs</a> property :-).</p> <p>Hopefully, this post also provides a simple example of how <a href="http://dbpedia.org/resource/Web_Ontology_Language" id="link-id158a3fe8">OWL</a> facilitates "Reasonable Linked Data". </p> <h3>Related</h3> <ul> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1455" id="link-id164e19f8">State of the Linked Data Web</a> </li> <li> <a href="http://www.mkbergman.com/?p=474" id="link-id11973d10">Making Linked Data Reasonable Using Description Logics Series</a> - post by <a href="http://community.linkeddata.org/dataspace/person/mkbergman#this" id="link-id1184bfb8">Mike Bergman</a> </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-05-06T14:26:15.000034-04:00
Linked Data & Identity
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1547
2009-04-29T20:05:58Z
<blockquote> <cite>A person, organization, place, idea, subject matter topic/heading, and other real world things possess "identity" -- that is, a constellation of characteristics that distinguish them from any other identity. Associated with this abstraction can be a label used as a reference, or "identifier". This is the distinction between a thing and the name of the thing.</cite> </blockquote> <blockquote> <p>section from <a href="http://www.ietf.org/internet-drafts/draft-ietf-dkim-overview-11.txt" id="link-id15a13d40">IETF's Domain Keys spec</a>. (paraphrased by <a href="http://myopenlink.net/dataspace/person/kidehen#this" id="link-id13d88ed8">me</a>) </p>.</blockquote> <p>The <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id11d5b9a8">Linked Data meme</a> is based on the use of HTTP based URIs as reference / identifier labels associated with the "identity abstraction" referred to above. Thus, when you de-reference (request <a href="http://dbpedia.org/resource/Information" id="link-id14706fb8">information</a> about) an HTTP based <a href="http://dbpedia.org/resource/Uniform_Resource_Identifier" id="link-id12b4ea50">URI</a> you ultimately end up with a resource <a href="http://dbpedia.org/resource/Uniform_Resource_Locator" id="link-id12127e20">URL</a> that exposes the "constellation of characteristics" mentioned above, in a representation negotiated at request time -- between an HTTP client and server e.g., (X)HTML, JSON, XML, RDF/XML, N3, Turtle, Trix, others :-)</p> <h3>Related</h3> <ul> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1546" id="link-id11b67288">What is the Linked Data meme About?</a> </li> <li> <a href="http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com%27s%20BLOG%20%5B127%5D/1543" id="link-id151fa890">Simple Explanation of RDF & Linked Data Dynamics</a>.</li> <li> <a href="http://www.handle.net/" id="link-id11d9cd30">Handle</a> -- <a href="http://dbpedia.org/resource/Internet" id="link-id0x131986f0">Internet</a> wide Identity Scheme and Resolution System</li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-05-01T12:25:49-04:00
What is the Linked Data Meme about?
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1546
2009-04-29T15:32:49Z
<p>The act of using URIs to "refer to" (reference) <a href="http://dbpedia.org/resource/World_Wide_Web">Web</a> addressable <a href="http://dbpedia.org/resource/Data">data</a> objects. It's also the act of using the same <a href="http://dbpedia.org/resource/Uniform_Resource_Identifier" id="link-id12b41fc0">URI</a> to de-reference the description of a referenced data object; in this case, the representation of the description is negotiated by a Web client and/or Web server. Thus, you can access the description of a data object via data representation formats such as: JSON, XML, (X)HTML, RDF/XML, N3, Turtle, TriX etc. </p> <p> <strong>Note:</strong> In proper Web parlance, a data object is referred to as a resource.</p> <h3>Simple example (using <a href="http://dbpedia.org/resource/DBpedia" id="link-id0x131005a0">DBpedia</a>)</h3> <p>In the <a href="http://dbpedia.org/resource/Linked_Data" id="link-id0x13299d20">Linked Data</a> realm, If you want to make a reference to the <a href="http://www.w3.org/DesignIssues/LinkedData.html" id="link-id0x188210a8">Linked Data meme</a> in a <a href="http://dbpedia.org/resource/Blog" id="link-id0x158a3fc0">blog</a> post, you are better off using the resource <strong>URI</strong>: http://dbpedia.org/resource/Linked_Data, instead of the Web page <strong><a href="http://dbpedia.org/resource/Uniform_Resource_Locator" id="link-id0x142865b0">URL</a></strong>: http://dbpedia.org/page/Linked_Data, which is the address of a physical document (an <a href="http://dbpedia.org/resource/Information" id="link-id0x15884030">information</a> conveying artifact) that at best visually presents the negotiated representation of a resource description.</p> <h3>Why is this valuable?</h3> <p>In the simplest sense, you only have one focal point for referencing (referring to) and de-referencing (retrieving data about) a given Web resource. It protects you from the impact of Web document location changes (amongst many other things).</p> <p>Remember, a single URI is a conduit into a realm where the identity, access, representation, presentation, and storage of a resource (data object) are completely distinct. It's the mechanism for conducting data across network, machine, operating system, dbms engine, application, and service (API) boundaries. Thus, without "linked data meme" prescribed URI referencing and de-referencing, we are simply back to "business as usual" re. the industry at large, where networks, operating systems, dbms engines, applications, and services (APIs) become the basis for "data lock-in" and silo construction.</p> <h3>Going forward</h3> <p>Take a second to think about the profound virtues of the ubiquitous Web of Linked Document URLs that we have today, and then apply that thinking to the burgeoning Web of Linked Data URIs, that has just turned corner and heading in everyone's direction at full blast.</p> <p> <strong>Note to "Social Media" players:</strong> Who you know isn't the canonical object of sociality. What you are i.e., your description and the data objects it exposes, are real objects of your sociality :-)</p> <h3>Related</h3> <ul> <li> <a href="http://www.openlinksw.com/weblog/public/search.vspx?blogid=127&q=%22Linked%20Data%22&type=text&output=html" id="link-id14d44430">Other post in this Blog Data Space associated with "Linked Data"</a>. </li> </ul>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-04-29T16:31:10-04:00
Simple Explanation of RDF and Linked Data Dynamics
http://www.openlinksw.com/blog/kidehen@openlinksw.com/blog/?id=1543
2009-04-24T20:59:08Z
<h3>What is RDF?</h3> <p>The acronym stands for: Resource Description Framework. And that's just what it is.</p> <p>RDF is comprised of a <a href="http://dbpedia.org/resource/Data">Data</a> Model (<a href="http://dbpedia.org/resource/Entity-attribute-value_model" id="link-id11bb5cd8">EAV</a>/CR Graph) and Data Representation Formats such as: N3, Turtle, RDF/XML etc.</p> <p>RDF's essence is about: "Entities" and "Attributes" being <a href="http://dbpedia.org/resource/Uniform_Resource_Identifier" id="link-id14362100">URI</a> based, while "Values" may be URI or Literals (typed or untyped) based. </p> <p>URIs are <a href="http://dbpedia.org/resource/Entity" id="link-id139066e8">Entity</a> Identifiers.</p> <h3>What is <a href="http://dbpedia.org/resource/Linked_Data" id="link-id11ed5340">Linked Data</a>?</h3> <p>Short for "<a href="http://dbpedia.org/resource/World_Wide_Web">Web</a> of Linked Data" or "Linked Data <a href="http://dbpedia.org/resource/Giant_Global_Graph" id="link-id13f4b878">Web</a>".</p> <p>A term coined by <a href="http://www.w3.org/People/Berners-Lee/card#i" id="link-id117b4310">TimBL</a> that describes an HTTP based "<a href="http://dbpedia.org/resource/Reference_(computer_science)" id="link-id138fed30">data access by reference</a> pattern" that uses a single pointer or handle for "referring to" and "obtaining actual data about" an entity.</p> <p>Linked Data uses the deceptively simple messaging scheme of HTTP to deliver a granular entity reference and access mechanism that transcends traditional computing boundaries such as: operating system, application, database engines, and networks.</p> <h3>How are Linked Data & RDF Related?</h3> <p>Linked Data simply mandates the following re. RDF:</p> <ul> <li>URIs should be HTTP based so that you can "refer to" (Reference) an Entity, its Attributes, or URI based Attribute values via the Web (infact any HTTP based network e.g., Intranets and Extranets)</li> <li> URIs should also be HTTP based so that you can use them to de-reference resource descriptions via the Web (or Intranets and Extranets).</li> </ul> <p> <strong>Note:</strong> by Entity I am also referring to: a resource (Web parlance), data item, data object, real-world object, or datum. </p> <p>Linked Data is also about, using URIs and HTTP's content negotiation feature to separate: presentation, representation, access, and identity of data items. Even better, content negotiation can be driven by user agent and/or data server based quality of service algorithms (representation preference order schemes).</p> <p>To conclude, Linked Data is ultimately about the realization that: Data is the new Electricity, and it's conductors are URIs :-)</p> <p> <strong>Tip to governments of the world</strong>: we are in exponential times, the current downturn is but one side of the "exponential times ledger", the other side of the "exponential times ledger" is simply about unleashing "raw data" -- in structured form -- into the Web, so that "citizen analysts" can blossom and ultimately deliver the transparency desperately sought at every level of the economic value chain. Think: "raw data ready" whenever you ponder about "shovel ready" infrastructure projects!</p>
Kingsley Uyi Idehen
kidehen@openlinksw.com
2009-04-24T17:14:41-04:00