Kingsley Idehen's Typepad

The Cost of doing the Right Thing

One of the biggest impediments to the adoption of technology is the cost burden typically associated with doing the right thing. For instance, requirements for making the Linked Data Web (GGG) buzz would include the following (paraphrasing TimBL's original Linked Data meme):

-- identifying the things you observe, or stumble upon, using URIs (aka Entity IDs)

-- construct URIs using HTTP so that the Web provides a channel for referencing things elsewhere (remote object referencing)

-- Expose things in your Data Space(s) that are potentially useful to other Web users via URIs

-- Link to other Web accessible things using their URIs.

The list is nice, but actual execution can be challenging. For instance, when writing a blog post, or constructing a WikiWord, would you have enough disposable time to go searching for these URIs? Or would you compromise and continue to inject "Literal" values into the Web, leaving it to the reasoning endowed human reader to connect the dots?

Anyway, OpenLink Data Spaces is now equipped with a Glossary system that allows me to manage terms, meaning of terms, and hyper-linking of phrases and words matching associated with my terms. The great thing about all of this is that everything I do is scoped to my Data Space (my universe of discourse), I don't break or impede the other meanings of these terms outside my Data Space. The Glossary system can be shared with anyone I choose to share it with, and even better, it makes my upstreaming (rules based replication) style of blogging even more productive :-)

Remember, on the Linked Data Web, who you know doesn't matter as much as what your are connected to, directly or indirectly. Jason Kolb covers this issue in his post: People as Data Connectors, and so doesFrederick Giasson via a recent post titled: Networks are everywhere. For instance, this blog post (or the entire Blog) is a bona fide RDF Linked Data Source, you can use it as the Data Source of a SPARQL Query to find things that aren't even mentioned in this post, since all you are doing is beaming a query through my Data Space (a container of Linked Data Graphs). On that note, let's re-watch Jon Udell's "On-Demand-Blogosphere" screencast from 2006 :-)

rdfsemanticwebweb30sparqlhowtoscreencastopenlinkDataSpace

Semantic Web Patterns: A Guide to Semantic Technologies (Update 2)

For all the one-way feed consumers and aggregators, and readers of the original post, here is a variant equipped hyperlinked phrases as opposed to words. As I stated in the prior post, the post (like most of my posts) was part experiment / dog-fodding of automatic tagging and hyper-linking functionality in OpenLink Data Spaces.

ReadWriteWeb via Alex Iskold's post have delivered another iteration of their "Guide to Semantic Technologies".

If you look at the title of this post (and their article) they seem to be accurately providing a guide to Semantic Technologies, so no qualms there. If on the other hand, this is supposed to he a guide to the "Semantic Web" as prescribed by TimBL then they are completely missing the essence of the whole subject, and demonstrably so I may add, since the entities: "ReadWriteWeb" and "Alex Iskold" are only describable today via the attributes of the documents they publish i.e their respective blogs and hosted blog posts.

Preoccupation with Literal objects as describe above, implies we can only take what "ReadWriteWeb" and "Alex Iskold" say "Literally" (grep, regex, and XPath/Xquery are the only tools for searching deeper in this Literal realm), we have no sense of what makes them tick or where they come from, no history (bar "About Page" blurb), no data connections beyond anchored text (more pointers to opaque data sources) in post and blogrolls. The only connection between this post and them is the my deliberate use of the same literal text in the Title of this post.

TimBL's vision as espoused via the "Semantic Web" vision is about the production, consumption, and sharing of Data Objects via HTTP based Identifiers called URIs/IRIs (Hyperdata Links / Linked Data). It's how we use the Web as a Distributed Database where (as Jim Hendler once stated with immense clarity): I can point to records (entity instances) in your database (aka Data Space) from mine. Which is to say that if we can all point to data entities/objects (not just data entities of type "Document") using these Location, Value, and Structure independent Object Identifiers (courtesy of HTTP) we end up with a much more powerful Web, and one that is closer to the "Federated and Open" nature of the Web.

As I stated in a prior post, if you or your platform of choice aren't producing de-referencable URIs for your data objects, you may be Semantic (this data model predates the Web), but there is no "World Wide Web" in what you are doing.

What are the Benefits of the Semantic Web?

Consumer - "Discovery of relevant things" and be being "Discovered by relevant things" (people, places, events, and other things)

Enterprise - ditto plus the addition of enterprise domain specific things such as market opportunities, product portfolios, human resources, partners, customers, competitors, co-opetitors, acquisition targets, new regulation etc..)

Simple demo:

I am a Kingsley Idehen, a Person who authors this weblog. I also share bookmarks gathered over the years across an array of subjects via my bookmark data space. I also subscribe to a number of RSS/Atom/RDF feeds, which I share via my feeds subscription data space. Of course, all of these data sources have Tags which are collectively exposed via my weblog tag-cloud, feeds subscriptions tag-cloud, and bookmarks tag-cloud data spaces.

As I don't like repeating myself, and I hate wasting my time or the time of others, I simply share my Data Space (a collection of all of my purpose specific data spaces) via the Web so that others (friends, family, employees, partners, customers, project collaborators, competitors, co-opetitors etc.) can can intentionally or serendipitously discover relevant data en route to creating new information (perspectives) that is hopefully exposed others via the Web.

Bottom-line, the Semantic Web is about adding the missing "Open Data Access & Connectivity" feature to the current Document Web (we have to beyond regex, grep, xpath, xquery, full text search, and other literal scrapping approaches). The Linked Data Web of de-referencable data object URIs is the critical foundation layer that makes this feasible.

Remember, It's not about "Applications" it's about Data and actually freeing Data from the "tyranny of Applications". Unfortunately, application inadvertently always create silos (esp. on the Web) since entity data modeling, open data access, and other database technology realm matters, remain of secondary interest to many application developers.

Final comment, RDF facilitates Linked Data on the Web, but all RDF isn't endowed with de-referencable URIs (a major source of confusion and misunderstanding). Thus, you can have RDF Data Source Providers that simply project RDF data silos via Web Services APIs if RDF output emanating from a Web Service doesn't provide out-bound pathways to other data via de-referencable URIs. Of course the same also applies to Widgets that present you with all the things they've discovered without exposing de-referencable URIs for each item.

BTW - my final comments above aren't in anyway incongruent with devising successful business models for the Web. As you may or may not know, OpenLink is not only a major platform provider for the Semantic Web (expressed in our UDA, Virtuoso, OpenLink Data Spaces, and OAT products), we are also actively seeding Semantic Web (tribe: Linked Data of course) startups. For instance, Ztigist, which now has Mike Bergman as it's CEO alongside Frederick Giasson as CTO. Of course, I cannot do Zitgist justice via a footnote in a blog post, so I will expand further in a separate post.

Additional information about this blog post:

1. I didn't spent hours looking for URIs used in my hyperlinks
2. The post is best viewed via an RDF Linked Data aware user agents (OpenLink RDF Browser, Zitgist Data Viewer, DISCO Hyperdata Browser, Tabulator).

webservicesajaxatomrdfrssxpathxmlxquerysemanticwebweb30historyoatopenlinkvirtuosoDataSpace

Semantic Web Patterns: A Guide to Semantic Technologies (Update 1)

ReadWriteWeb via Alex Iskold have delivered another iteration of their "Guide to Semantic Technologies".

If you look at the title of this post (and their article) they seem to be accurately providing a guide to Semantic Technologies, so no qualms there. If on the other hand, this is supposed to he a guide to the "Semantic Web" as prescribed by TimBL then they are completely missing the essence of the whole subject, and demonstrably so I may add, since the entities: "ReadWriteWeb" and "Alex Iskold" are only describable today via the attributes of the documents they publish i.e their respective blogs and hosted blog posts.

Preoccupation with Literal objects as describe above, implies we can only take what "ReadWriteWeb" and "Alex Iskold" say "Literally" (grep, regex, and XPath/Xquery are the only tools for searching deeper in this Literal realm), we have no sense of what makes them tick or where they come from, no history (bar "About Page" blurb), no data connections beyond anchored text (more pointers to opaque data sources) in post and blogrolls. The only connection between this post and them is the my deliberate use of the same literal text in the Title of this post.

TimBL's vision as espoused via the "Semantic Web" vision is about the production, consumption, and sharing of Data Objects via HTTP based Identifiers called URIs/IRIs (Hyperdata Links / Linked Data). It's how we use the Web as a Distributed Database where (as Jim Hendler once stated with immense clarity): I can point to records (entity instances) in your database (aka Data Space) from mine. Which is to say that if we can all point to data entities/objects (not just data entities of type "Document") using these Location, Value, and Structure independent Object Identifiers (courtesy of HTTP) we end up with a much more powerful Web, and one that is closer to the "Federated and Open" nature of the Web.

As I stated in a prior post, if you or your platform of choice aren't producing de-referencable URIs for your data objects, you may be Semantic (this data model predates the Web), but there is no "World Wide Web" in what you are doing.

What are the Benefits of the Semantic Web?

Consumer - "Discovery of relevant things" and be being "Discovered by relevant things" (people, places, events, and other things)

Enterprise - ditto plus the addition of enterprise domain specific things such as market opportunities, product portfolios, human resources, partners, customers, competitors, co-opetitors, acquisition targets, new regulation etc..)

Simple demo:

I am a Kingsley Idehen, a Person who authors this weblog. I also share bookmarks gathered over the years across an array of subjects via my bookmark data space. I also subscribe to a number of RSS/Atom/RDF feeds, which I share via my feeds subscription data space. Of course, all of these data sources have Tags which are collectively exposed via my weblog tag-cloud, feeds subscriptions tag-cloud, and bookmarks tag-cloud data spaces.

As I don't like repeating myself, and I hate wasting my time or the time of others, I simply share my Data Space (a collection of all of my purpose specific data spaces) via the Web so that others (friends, family, employees, partners, customers, project collaborators, competitors, co-opetitors etc.) can can intentionally or serendipitously discover relevant data en route to creating new information (perspectives) that is hopefully exposed others via the Web.

Bottom-line, the Semantic Web is about adding the missing "Open Data Access & Connectivity" feature to the current Document Web (we have to beyond regex, grep, xpath, xquery, full text search, and other literal scrapping approaches). The Linked Data Web of de-referencable data object URIs is the critical foundation layer that makes this feasible.

Remember, It's not about "Applications" it's about Data and actually freeing Data from the "tyranny of Applications". Unfortunately, application inadvertently always create silos (esp. on the Web) since entity data modeling, open data access, and other database technology realm matters, remain of secondary interest to many application developers.

Final comment, RDF facilitates Linked Data on the Web, but all RDF isn't endowed with de-referencable URIs (a major source of confusion and misunderstanding). Thus, you can have RDF Data Source Providers that simply project RDF data silos via Web Services APIs if RDF output emanating from a Web Service doesn't provide out-bound pathways to other data via de-referencable URIs. Of course the same also applies to Widgets that present you with all the things they've discovered without exposing de-referencable URIs for each item.

BTW - my final comments above aren't in anyway incongruent with devising successful business models for the Web. As you may or may not know, OpenLink is not only a major platform provider for the Semantic Web (expressed in our UDA, Virtuoso, OpenLink Data Spaces, and OAT products), we are also actively seeding Semantic Web (tribe: Linked Data of course) startups. For instance, Ztigist, which now has Mike Bergman as it's CEO alongside Frederick Giasson as CTO. Of course, I cannot do Zitgist justice via a footnote in a blog post, so I will expand further in a separate post.

Additional information about this blog post:

1. I didn't spent hours looking for URIs used in my hyperlinks
2. The post is best viewed via an RDF Linked Data aware user agents (OpenLink RDF Browser, Zitgist Data Viewer, DISCO Hyperdata Browser, Tabulator).

webservicesajaxatomrdfrssxpathxmlxquerysemanticwebweb30historyoatopenlinkvirtuosoDataSpace

Linked Data is vital to Enterprise Integration driven Agility

John Schmidt, from Informatica, penned an interesting post titled: IT Doesn't Matter - Integration Does.

Yes, integration is hard, but I do profoundly believe that what's been happening on the Web over the last 10 or so years also applies to the Enterprise, and by this I absolutely do not mean "Enterprise 2.0" since "2.0" and productive agility do not compute in my realm of discourse.

large collections of RSS feeds, Wikiwords, Shared Bookmarks, Discussion Forums etc.. when disconnected at the data level (i.e. hosted in pages with no access to the "data behind") simply offer information deluge and inertia (there are only so many hours for processing opaque information sources in a given day).

Enterprises fundamentally need to process information efficiently as part of a perpetual assessment of their relative competitive Strengths, Weaknesses, Opportunities, and Threats (SWOT), in existing and/or future markets. Historically, IT acquisitions have run counter intuitively to the aforementioned quest for "Ability" due to the predominance of "rip and replace" approach technology acquisition that repeatedly creates and perpetuates information silos across Application, Database, Operating System, Development Environment boundaries. The sequence of events typically occurs as follows:

1. applications are acquired on a problem by problem basis
2. back-end application databases are discovered once ad-hoc information views are sought by information workers
3. back-end database disparity across applications is discovered once holistic views are sought by knowledge workers (typically domain experts).

In the early to mid 90's (pre ubiquitous Web), operating system, programming language, operating system, and development framework independence inside the enterprise was technically achievable via ODBC (due to it's platform independence). That said, DBMS specific ODBC channels alone couldn't address the holistic requirements associated with Conceptual Views of disparate data sources, hence the need for Data Access Virtualization via Virtual Database Engine technology.

Just as is the case on the Web today, with the emergence of the "Linked Data" meme, enterprises now have a powerful mechanism for exploiting the Data Integration benefits associated with generating Data Objects from disparate data sources, endowed with HTTP based IDs (URIs).

Conceptualizing access to data exposed Databases APIs, SOA based Web Services (SOAP style Web Services), Web 2.0 APIs (REST style Web Services), XML Views of SQL Data (SQLX), pure XML etc.. is problem area addressed by RDF aware middleware (RDFizers e.g Virtuoso Sponger).

Here are examples of what SQL Rows exposed as RDF Data Objects (identified using HTTP based URIs) would look like outside or behind a corporate firewall :

Customer - Alfreds Futterkiste

Customer Contact - Maria Anders

Salesrep - Nancy Davolio

Customer Orders Numbers - 11084, 11011, 11078, 11085

What's Good for the Web Goose (Personal Data Space URIs) is good for the Enterprise Gander (Enterprise Data Space URIs).

Related

Data Access - A Cultural or Technical Challenge?

Semantic Web Advocate of Tribe Linked Data! (Updated)

These days I increasingly qualify myself and my Semantic Web advocacy as falling under the realm Linked Data. Thus, I tend to use the following introduction: I am Kingsley Idehen, of the Tribe Linked Data.

The aforementioned qualification is increasingly necessary for the following reasons:

1. The Semantic Web vision is broad and comprised of many layers
2. A new era of confusion is taking shape just as we thought we had quelled the prior AI dominated realm of confusion
3. None of the Semantic Web vision layers are comprehensible in practical ways without a basic foundation
4. Open Data Access is the foundation of the Semantic Web (in prior post I used the term: Semantic Web Layer 1)
5. URIs units of Open Data Access in Semantic Web parlance i.e.. each datum on the Web must have an ID (minted by the host Data Space).

The terms GGG, Linked Data, Data Web, Web of Data, and Web 3.0 (when I use this term) all imply URI driven Open Data Access for the Web Database (maybe call this ODBC for the Web) -- ability to point to records across data spaces without any adverse effect to the remote data spaces. It's really important to note that none of the aforementioned terms have nothing to do with the "Linguistic Meaning of blurb". Building a smarter document exposed via a URL without exposing descriptive data links doesn't provide open access to information data sources.

As human beings we are all endowed with reasoning capability. But we can't reason without access to data. Dearth of openly accessible structured data is the source of many ills in cyberspace and across society in general. Today we still have Subjectivity reigning over Objectivity due to the prohibitive costs of open data access.

We can't cost-effectively pursue objectivity without cost-effective infrastructure for creating alternative views of the data behind information sources (e.g. Web Pages). More Objectivity and less Subjectivity is what the next Web Frontier is about. At OpenLink we simply use the moniker: Analysis for All! Everyone becomes a data analyst in some form, and even better, the analysis are easily accessible to anyone connected to the Web. Of course, you will be able to share special analysis with your private network of friends and family, or if you so choose, not at all :-)

Recap, it's important to note that Linked Data is the foundation layer of the Semantic Web vision. It's not only facilitates open data access, it also enables data integration (Meshing as opposed to Mashing) across disparate data schemas

As demonstrated by DBpedia and the Linked Data Solar system emerging around it, if you URI everything, then everything is Cool.

Linked Data and Information Silos are mutually exclusive concepts. Thus, you cannot produce a web accessible Information Silo and then refer to it as "Semantic Web" technology. Of course, it might be very Semantic, but it's fundamentally devoid of critical "Semantic Web" essence (DNA).

My acid test for any Semantic Web solution is simply this (using a Web User Agent or Client):

1. go to the profile page of the service
2. ask for an RDF representation of my profile (by this I mean "get me the raw data in structured form")
3. attempt to traverse the structured data graph (RDF) that the service provides via live de-referncable URIs.

Here is the Acid test against my Data Space:

1. My Profile Page (HTML representation dispatched via an instance of OpenLink Data Spaces)
2. Click on the "Linked Data Tab" (HTML representation endowed with Data Links the link to information resources containing other structured descriptions of things).

So, What Does "HREF" Stand For, Anyway

As per usual I am writing this post with the aim of killing a number of meme-birds with a single post in relation to the emerging Linked Data Web.

*On* the ubiquitous Web of "Linked Documents", HREF means (by definition and usage): Hypertext Reference to an HTTP accessible Data Object of Type: "Document" (an information resource). Of course we don't make the formal connection of Object Type when dealing with the Web on a daily basis, but whenever you encounter the "resource not found" condition notice the message: HTTP/1.0 404 Object Not Found, from the HTTP Server tasked with retrieving and returning the resource.

*In* the Web of "Linked Data", a complimentary addition to the current Web of "Linked Documents", HREF is used to reference Data Objects that are of a variety of "Types", not just "Documents". And the way this is achieved, is by using Data Object Identifiers (URIs / IRIs that are generated by the Linked Data deployment platform) in the strict sense i.e. Data Identity (URI) is separated from Data Address (URL). Thus, you can reference a Person Data Object (aka an instance of a Person Class) in your HREF and the HTTP Server returns a Description of the Data Object via a Document (again, an information resource). A document containing the Description of a Data Object typically contains HREFs to other Data Objects that expose the Attributes and Relationships of the initial Person Data Object, and it this collection of Data Objects that is technically called a "Graph" -- which is what RDF models.

What I describe above is basic stuff for anyone that's familiar with Object Database or Distributed Objects technology and concepts.

URI and URL confusion

The Linked Document Web is a collection of physical resources that traverse the Web Information Bus in palatable format i.e documents. Thus, Document Object Identity and Document Object Data Address can be the same thing i.e. a URL can serve as the ID/URI of a Document Data Object.

The Linked Data Web on the other hand, is a Distributed Object Database, and each Data Object must be uniquely defined, otherwise we introduce ambiguity that ultimately taints the Database itself (making incomprehensible to reasoning challenged machines). Thus we must have unique Object IDs (URIs / IRIs) for People, Places, Events, and other things that aren't Documents. Once we follow the time tested rules of Identity, People can then be associated with the things they create (blog posts, web pages, bookmarks, wikiwords etc). RDF is about expressing these graph model relationships while RDF serialization formats enables the information resources to transport these data object link ladden information resources to requesting User Agents.

Put in more succinct terms, all documents on the Web are compound documents in reality (e.g. mast contain a least an image these days). The Linked Data Web is about a Web where Data Object IDs (URIs) enable us to distill source data from the information contained in a compound document.

Examples:

1. <http://community.linkeddata.org/dataspace/person/kidehen2#this> - the ID (URI minted from URL via addition of #this) of a Data Object of Type Person that Identifies me. The Person definition I use comes from the FOAF vocabulary/schema/ontology/data dictionary
2. <http://community.linkeddata.org/dataspace/person/kidehen2> - the URI (also a URL) of a FOAF file that contains a description of the Data Object ID: <http://community.linkeddata.org/dataspace/person/kidehen2#this> (me)
3. As an information resource <http://community.linkeddata.org/dataspace/person/kidehen2> can be dispatched from an HTTP server to a User Agent in (X)HTML, RDF/XML, N3/Turtle representations via HTTP Content Negotiation (note: Look at the "Linked Data" tab to see one example of what Data Links facilitate re. Data Discovery and Exploration)
4. If I choose an Object ID of <http://community.linkeddata.org/dataspace/person/kidehen2/this> instead of <http://community.linkeddata.org/dataspace/person/kidehen2#this> then the HTTP Server should not return an information resource (i.e provide 200 OK response) when a User Agent requests a resource via HTTP using the URI: <http://community.linkeddata.org/dataspace/person/kidehen2/this>, because a Data Object ID (URI) and the Data Object Address (URL) cannot be the same when my Data Object isn't of Type Document; the sever has to use response code 303 to redirect the user agent to the URL of an information resource that matches the Content-type designated in the HTTP Request or determine representation based on it's own quality of service rules for the information resource associated with the Object ID (URI).

The degree of unobtrusiveness of new technology, concepts, or new applications of existing technology, is what ultimately determines eventual uptake and meme virulence (network effects). For a while, the Semantic Web meme was mired in confusion and general misunderstanding due to a shortage of practical use case scenario demos.

The emergence of the SPARQL Query Language has provided critical infrastructure for a number of products, projects, and demos, that now make the utility of the Semantic Web vision mush clearly via the simplicity of Linked Data, as exemplified by the following:

1. Linking Open Data Community - collection of People and Linked Data Spaces (across a variety of domains)
2. DBpedia - Ground zero for experiencing and comprehending Linked Data
3. OpenLink Data Spaces - a simple solution for creating Linked Data Web presence via from existing Web Data Sources (Blogs, Wikis, Shared Bookmarks, Tag Spaces, Web Sites, Social Networking Services, Web Services, Discussion Forums etc..)
4. OpenLink Virtuoso - a Universal Server for generating, managing, and deploying RDF Linked Data from SQL, XML, Web Services based data sources

Why Is This Post a Linked Data Demo, Again? Place the permalink of this post in a Linked Data aware user agent (OpenLink RDF Browser1, OpenLink RDF Browser2, Zitgist, DISCO, Tabulator), and the you can see the universal of interlinked data exposed by this post. The Title of this post should not be the sole mechanism for determining that it is Linked to other posts about the same topic.

Related

Ryan Tomayko's post titled: So, What Does "HREF" Stand For, Anyway

Elias Torre's post titled: The Web FTW

Cool URIs for the Semantic Web.

webservicesrdfxmlsemanticwebweb30foafsparqlsocialnetworkingopenlinkvirtuosoDataSpace

So, What Does "HREF" Stand For, Anyway

As per usual I am writing this post with the aim of killing a number of meme-birds with a single post in relation to the emerging Linked Data Web.

*On* the ubiquitous Web of "Linked Documents", HREF means (by definition and usage): Hypertext Reference to an HTTP accessible Data Object of Type: "Document" (an information resource). Of course we don't make the formal connection of Object Type when dealing with the Web on a daily basis, but whenever you encounter the "resource not found" condition notice the message: HTTP/1.0 404 Object Not Found, from the HTTP Server tasked with retrieving and returning the resource.

*In* the Web of "Linked Data", a complimentary addition to the current Web of "Linked Documents", HREF is used to reference Data Objects that are of a variety of "Types", not just "Documents". And the way this is achieved, is by using Data Object Identifiers (URIs / IRIs that are generated by the Linked Data deployment platform) in the strict sense i.e. Data Identity (URI) is separated from Data Address (URL). Thus, you can reference a Person Data Object (aka an instance of a Person Class) in your HREF and the HTTP Server returns a Description of the Data Object via a Document (again, an information resource). A document containing the Description of a Data Object typically contains HREFs to other Data Objects that expose the Attributes and Relationships of the initial Person Data Object, and it this collection of Data Objects that is technically called a "Graph" -- which is what RDF models.

What I describe above is basic stuff for anyone that's familiar with Object Database or Distributed Objects technology and concepts.

URI and URL confusion

The Linked Document Web is a collection of physical resources that traverse the Web Information Bus in palatable format i.e documents. Thus, Document Object Identity and Document Object Data Address can be the same thing i.e. a URL can serve as the ID/URI of a Document Data Object.

The Linked Data Web on the other hand, is a Distributed Object Database, and each Data Object must be uniquely defined, otherwise we introduce ambiguity that ultimately taints the Database itself (making incomprehensible to reasoning challenged machines). Thus we must have unique Object IDs (URIs / IRIs) for People, Places, Events, and other things that aren't Documents. Once we follow the time tested rules of Identity, People can then be associated with the things they create (blog posts, web pages, bookmarks, wikiwords etc). RDF is about expressing these graph model relationships while RDF serialization formats enables the information resources to transport these data object link ladden information resources to requesting User Agents.

Put in more succinct terms, all documents on the Web are compound documents in reality (e.g. mast contain a least an image these days). The Linked Data Web is about a Web where Data Object IDs (URIs) enable us to distill source data from the information contained in a compound document.

Examples:

1. <http://community.linkeddata.org/dataspace/person/kidehen2#this> - the ID (URI minted from URL via addition of #this) of a Data Object of Type Person that Identifies me. The Person definition I use comes from the FOAF vocabulary/schema/ontology/data dictionary
2. <http://community.linkeddata.org/dataspace/person/kidehen2> - the URI (also a URL) of a FOAF file that contains a description of the Data Object ID: <http://community.linkeddata.org/dataspace/person/kidehen2#this> (me)
3. As an information resource <http://community.linkeddata.org/dataspace/person/kidehen2> can be dispatched from an HTTP server to a User Agent in (X)HTML, RDF/XML, N3/Turtle representations via HTTP Content Negotiation (note: Look at the "Linked Data" tab to see one example of what Data Links facilitate re. Data Discovery and Exploration)
4. If I choose an Object ID of <http://community.linkeddata.org/dataspace/person/kidehen2/this> instead of <http://community.linkeddata.org/dataspace/person/kidehen2#this> then the HTTP Server should not return an information resource (i.e provide 200 OK response) when a User Agent requests a resource via HTTP using the URI: <http://community.linkeddata.org/dataspace/person/kidehen2/this>, because a Data Object ID (URI) and the Data Object Address (URL) cannot be the same when my Data Object isn't of Type Document; the sever has to use response code 303 to redirect the user agent to the URL of an information resource that matches the Content-type designated in the HTTP Request or determine representation based on it's own quality of service rules for the information resource associated with the Object ID (URI).

The degree of unobtrusiveness of new technology, concepts, or new applications of existing technology, is what ultimately determines eventual uptake and meme virulence (network effects). For a while, the Semantic Web meme was mired in confusion and general misunderstanding due to a shortage of practical use case scenario demos.

The emergence of the SPARQL Query Language has provided critical infrastructure for a number of products, projects, and demos, that now make the utility of the Semantic Web vision mush clearly via the simplicity of Linked Data, as exemplified by the following:

1. Linking Open Data Community - collection of People and Linked Data Spaces (across a variety of domains)
2. DBpedia - Ground zero for experiencing and comprehending Linked Data
3. OpenLink Data Spaces - a simple solution for creating Linked Data Web presence via from existing Web Data Sources (Blogs, Wikis, Shared Bookmarks, Tag Spaces, Web Sites, Social Networking Services, Web Services, Discussion Forums etc..)
4. OpenLink Virtuoso - a Universal Server for generating, managing, and deploying RDF Linked Data from SQL, XML, Web Services based data sources

Why Is This Post a Linked Data Demo, Again? Place the permalink of this post in a Linked Data aware user agent (OpenLink RDF Browser1, OpenLink RDF Browser2, Zitgist, DISCO, Tabulator), and the you can see the universal of interlinked data exposed by this post. The Title of this post should not be the sole mechanism for determining that it is Linked to other posts about the same topic.

Related

Ryan Tomayko's post titled: So, What Does "HREF" Stand For, Anyway

Elias Torre's post titled: The Web FTW

Cool URIs for the Semantic Web.

New W3C Incubator Group: Relational Database to RDF Mapping

The new RDB2RDF Incubator Group is now official. The group is sponsored by Oracle, HP, PartnersHealth, and OpenLink Software.

Goals

The goal of this effort is standardization of approaches (syntax and methodology) for mapping Relational Data Model instance data to RDF (Graph Data Model).

Benefits

Every record in a relational table/view/stored procedure (Table Valued Functions/Procedures) is declaratively morphed into an Entity (instance of a Class associated with a Schema/Ontology). The derived entities become part of a graph that exposes relationships and relationship traversal paths that have lower JOIN Costs than attempting the same thing directly via SQL. In a nutshell, you end up with a conceptual interface atop a logical data layer that enables a much more productive mechanism for exploring homogeneous and/or heterogeneous data without confinement at the DB instance, SQL DBMS type, host operating system, local area network, or wide area network levels.

Just as we have to mesh the Linked Data and Document Webs, unobtrusively. It's also important that the same principles to apply to exposure of RDBMS hosted data as RDF based Linked Data.

We all know that a large amount of data driving the IT engines of most enterprises resides in Relational Databases. And contrary to recent RDBMS vs RDF database misunderstandings espoused (hopefully inadvertently) by some commentators, Relational Database engines aren't going away anytime soon. Meshing Relational (logical) and Graph (conceptual) data models a natural progression along an evolutionary path towards: Analysis for All. By the way, there is a parallel evolution occurring in others realms such as Microsoft's ADO.NET's Entity Framework.

How would I use RDB2RDF Mapping?

To Unobtrusively expose existing data sources as RDF Linked Data. The links that follow provide examples:

-- Enterprise Databases e.g. Northwind SQL Database as Linked Data (Zitgist View, OpenLink RDF Browser View, DISCO Browser View, Tabulator View)

-- Content Management e.g. Drupal hosted Blog Posts as Linked Data

-- Weblog Platform e.g. Wordpress hosted Blog Posts as Linked Data

-- Wiki Platform e.g. MediaWiki hosted Wikiwords as Linked Data

Related

1. Virtuoso's Meta Schema Language for Declaratively generating RDF Views of SQL Data (Presentation, White Paper, Tutorial, and Online Docs)
2. ESW Wiki's Collection of SQL-RDF Mapping Tools
3. What the Semantic Web means for your Business

My 5 Favorite Things about Linked Data on the Web

1. End to Buzzword Blur - how buzzwords are used to obscure comprehension of core concepts. Let SKOS, MOAT, SCOT reign!
2. End of Data Silos - you don't own me, my data, my data's mobility (import/export), or accessibility (by reference) just because I signed up for Yet Another Software as Service (ySaaS)
3. End of Misinformation - Sins of omission will no longer go unpunished the era of self induced amnesia due to competitive concerns is over, Co-opetition shall reign (Ray Noorda always envisoned this reality)
4. Serendipitous information and data discovery gets cheaper by the second - you're only a link away for a universe of relevant and accessible data
5. Rise of Quality - Contrary to historic president (due to all of the above) well engineered solutions will no longer be sure indicators of commercial failure

BTW - Benjamin Nowack penned an interesting post titled: Semantic Web Aliases, that covers a variety of labels used to describe the Semantic Web. The great thing about this post is that it provides yet another demonstration-in-the-making for the virtues of Linked Data :-)

Labels are harmless when their sole purpose is the creation of routes of comprehension for concepts. Unfortunately, Labels aren't always constructed with concept comprehension in mind, most of the time they are artificial inflectors and deflectors servicing marketing communications goals.

Anyway, irrespective of actual intent, I've endowed all of the labels from Bengee's post with URIs as my contribution important disambiguation effort re. the Semantic Web:

• Semantic Web (timbl)
• Web of Data (timbl)
• lowercase semantic [wW]eb (tantek)
• Semantic Web 2.0 (by stefandecker, IIRC)
• Web 3.0 (by nova and others)
• Semantic Graph (by nova and others)
• Hyperdata (by danja) Linked Data (by timbl, and implemented by the Chris Bizer and Richard Cyganiak inspired, Linking Open Data Community and it's poster project DBpedia)
• Linked Data Web (by kidehen)
• Structured Web (by mkbergman)
• Semantic Data Web (by kidehen)
• SemWeb (by the developer community)
• GGG - The Giant Global Graph (by timbl) Web 3G (by iand)

As per usual this post is best appreciated when processed via an Linked Data aware user agent.

Driving Lanes on the Web based Information Super Highway

Post absorption of Web 3G commentary emanating from the Talis blog space. Ian Davis appears to be expending energy on the definition of, and timeframes for, the next Web Frontier (which is actually here btw) :-)

Daniel Lewis also penned an interesting post in response to Ian's, that actually triggered this post.

I think definition time has long expired re. the Web's many interaction dimensions, evolutionary stages, and versions.

On my watch it's simply demo / dog-food time. Or as Dan Brickley states: Just Show It.

Below, I've created a tabulated view of the various lanes on the Web's Information Super Highway. Of course, this is a Linked Data demo should you be interested in the universe of data exposed via the links embedded in this post :-)

The Web's Information Super Highway Lanes

	1.0	2.0	3.0
Desire	Information Creation & Retrieval	Information Creation, Retrieval, and Extraction	Distillation of Data from Information
Meme	Information Linkage (Hypertext)	Information Mashing (Mash-ups)	Linked Data Meshing (Hyperdata)
Enabling Protocol	HTTP	HTTP	HTTP
Markup	HTML	(X)HTML& various XML based formats (RSS, ATOM, others)	Turtle, N3, RDF/XML, others
Basic Data Unit	Resource (Data Object) of type "Document"	Resource (Data Object) of type "Document"	Resource (Data Object) that may be one of a variety of Types: Person, Place, Event, Music etc.
Basic Data Unit Identity	Resource URL (Web Data Object Address)	Resource URL (Web Data Object Address)	Unique Identifier (URI) that is indepenent of actual Resource (Web Data Object) Address. Note: An Identifier by itself has no utility beyond Identifying a place around which actual data may be clustered.
Query or Search	Full Text Search patterns	Full Text Search patterns	Structured Querying via SPARQL
Deployment	Web Server (Document Server)	Web Server + Web Services Deployment modules	Web Server + Linked Data Deployment modules (Data Server)
Auto-discovery	<link rel="alternate"..>	<link rel="alternate"..>	<link rel="alternate" | "meta"..>, basic and/or transparent content negotiation
Target User	Humans	Humans & Text extraction and manipulation oriented agents (Scrappers)	Agents with varying degrees of data processing intelligence and capacity
Serendipitous Discovery Quotient (SDQ)	Low	Low	High
Pain	Information Opacity	Information Silos	Data Graph Navigability (Quality)