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Linked Data, Proposal

Using Linked Data

Ok, so finally the IEEE Internet Computing article on Exploiting Linked Data to Build Web Applications is available. Though this is a nice first step, much more is needed to advance the field. The goal is to enable people to actually use linked data in their Web applications, rather than ‘only’ publish datasets. Don’t misunderstand me here: it is a good thing to publish on the Web of Data, but ultimately data is meant to be used somewhere, right? Publishing linked data is not an end in itself.

To support this effort, I’m currently compiling a technical report in and for DERI’s Linked Data Research Centre (LiDRC) that looks at current examples of linked data-driven Web applications, gathers good practices and discusses the anatomy of a typical application (in the last part of the report issues and challenges are discussed, as well). So, one of the central contributions is a proposed concept for linked data-driven Web applications, which renders as follows:

A concept of linked data-driven Web applications

The proposed components read as follows:

  • A local RDF store, able to cache results and act as a permanent storage device to track users, etc.. We note that an RDF store such as ARC2 or Virtuoso is not a strict requirement, though often it makes sense to manage the RDF data in a native environment.
  • Some logic (a controller) and UI modules implementing the business logic, the User Interface (UI) and the interaction parts of the application. These components are not specific to linked data-driven Web applications, however typically required and found in the wild.
  • A data integration component, focusing on fetching linked data from the Web of Data, either directly from the LOD cloud or via Semantic Indexer such as Sindice or Falcons.
  • A republishing component that eventually exposes parts of the application’s (interlinked) data on the Web of Data. It is a good practice to republish the application’s data, hence providing again input to the LOD cloud.

I’d be happy to hear from you what you think about this proposal. Any architectural feedback is welcome!


About woddiscovery

Web of Data researcher and practitioner


7 thoughts on “Using Linked Data

  1. Hope I got it right, but it looks that the proposed architecture is for web applications that are completely dependent on Linked data i.e. don’t use linked data to enrich their own “normal” web application. probably, most existing web application use linked data to add some information or extra services to their already-existing ones (like BBC music…). This kind of application needs essential review of the application, isn’t it?

    Posted by Fadi | 2009-07-26, 09:31
  2. Fadi,

    Thanks for your feedback. I think you’ve raised a very valid issue, indeed. There is, IMHO, actually a whole spectrum of possibilities ranging from simple usage of linked data (where data reuse is the main purpose) to a full-fledged linked data app that entirely depends on linked data and hopefully also produces linked data. I’ll put this into the report and in case you ping me with your full name, I’ll credit you, of course 😉

    Also, please note that this is a conceptual thing; some apps may not have all components on board and I don’t aim at defining the minimal requirements for a Web app to be qualified as a linked data Web app. All I did was basically reviewing existing linked data apps and tried to abstract away. A very bottom-up approach, so to speak. Compare this, if you like, with what the GoF did re patterns in software engineering …


    Posted by woddiscovery | 2009-07-26, 09:38
  3. I haven’t purchased the article but, assuming Logic and UI are to some extent universal, where in the rest of the diagram are the major components I already use to do my job?

    If you want to sell this fax machine you need to sell it to developers who don’t know anyone with a fax machine, and I think that means showing how it works with the other gadgets I’m already using to get stuff done.

    As Fadi says, most existing uses seem to be enhancing existing applications and existing applications use existing technologies. As an OO developer, the main issue for me is working RDF into my domain model without upsetting my ORM.

    Posted by Simon Gibbs | 2009-07-26, 10:15
  4. Simon,

    Thank you as well for the productive feedback. I think you are dead right regarding the selling point as well as your point re ‘existing applications use existing technologies’. I admit that the blog post does not cover the issue at hand in full depth and hence have to ask you to be a bit patient till the full report is available 😉

    I have to stress the point that this is very conceptual, though. Most of the stuff used out there, say, the MVC model available in RoR, can be directly used with respective RDF-based frameworks (e.g., ActiveRDF for Ruby, etc.). Further, I really want to focus on the linked data specific components (integrator and republisher) as these seem to me the really new contributions. For example, I’m interested in a good answer to the question: how can linked datasets be selected, based on certain requirements such as content (e.g., about books), interlinking (e.g., must interlink to DBpedia), licenses (e.g., must be available under ODbL), etc. – in my understanding this can be, for example, achieved using voiD descriptions along with a semantic indexer.


    Posted by woddiscovery | 2009-07-26, 10:30
  5. One growing application of Linked Data, that should have a viral aspect to it, is the one being developed in the Social Web space with foaf+ssl. http://esw.w3.org/topic/foaf+ssl

    Here one can start with very minimal linked data usage that has immediate advantages to all those who publish: it enables them to see their friends, family’s, groups’ or colleague’s information, photos, etc… Also it works as a simple sign on, authentication protocol, so it has immediate value even without the linked data component which should increase it’s adoption.

    Posted by Henry Story | 2009-07-26, 14:01
  6. Thanks Henry, and yes you’re right 😉

    Btw, the draft (first version) of the above mentioned report is now available: Linked Data Applications (some 5MB).

    Posted by woddiscovery | 2009-07-26, 21:15


  1. Pingback: Michael Hausenblas (mhausenblas) 's status on Sunday, 26-Jul-09 08:24:36 UTC - Identi.ca - 2009-07-26

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