Linked Data is Blooming: Why You Should Care
Last week we discussed how the current era of the Web is evolving. One of the concepts we noted was Linked Data, an idea whose time has come in 2009. Sir Tim Berners-Lee, the inventor of the Web, gave a must-view talk at the TED Conference earlier this year, evangelizing Linked Data. He said that Linked Data was a sea change akin to the invention of the WWW itself. We've gone from a Web of documents, via the WWW, to a Web of data. Berners-Lee is now on a crusade for everyone from government departments, to individuals, to open up their data and put it on the Web - so that others can link to it and use it. In this post we give a high-level overview of Linked Data. Read on to stop and smell the roses.
A great place to start to understand Linked Data is Sir Tim's TED talk, embedded below. It's just over 15 minutes and highly recommended if you want to grok where the Web is headed. The slides are also available.
Linked Data: An Idea Whose Time Has Come
Linked Data is an official W3C project. An independent community page for Linked Data describes it as "using the Web to connect related data that wasn't previously linked, or using the Web to lower the barriers to linking data currently linked using other methods."
Tim Berners-Lee described Linked Data as a grassroots movement in his TED presentation. The above image shows you how many participating data sets there are now (it'll have increased even more since then, as that was a March 2009 snapshot). Linked Data is ramping up fast. To give you an idea of how much it's grown over the past two years alone, here is a snapshot of the data sets that were available in May 2007:
Linked Data in a Nutshell
In a W3C memo that Berners-Lee published in July 2007, he described four principles of Linked Data. The Wikipedia paraphrased it as follows:
- Use URIs to identify things that you expose to the Web as resources.
- Use HTTP URIs so that people can locate and look up (dereference) these things.
- Provide useful information about the resource when its URI is dereferenced.
- Include links to other, related URIs in the exposed data as a means of improving information discovery on the Web.
Even that paraphrasing is a bit technical, but we can sum it up like so: Linked Data allows you to discover, connect to, describe, and re-use all kinds of data. It is to data what the World Wide Web was to documents back in the 90's.
W3C: Linked Data: Principles and State of the Art, April 2008
On ReadWriteWeb we've discussed Linked Data a number of times. Alexander Korth wrote a good high level intro last month. He noted that Linked Data builds on and interconnects existing ontologies such as WordNet, FOAF, and SKOS. He went on to explain that the data sets grant access to their knowledge bases and link to items in other data sets:
"The project follows basic design principles of the World Wide Web: simplicity, tolerance, modular design, and decentralization. The LOD [Linking Open Data] project currently counts more than 2 billion RDF triples, which is a lot of knowledge. (A triple is a piece of information that consists of a subject, predicate, and object to express a particular subject's property or relationship to another subject.) Also, the number of participating data sets is rapidly growing. The data sets currently can be accessed in heterogeneous ways; for example, through a semantic web browser or by being crawled by a semantic search engine."
Let A Thousand Flowers Bloom
If there's one idea we want to leave you with about Linked Data, it's that the data is there to be used. Linked Data enables data to be opened up and connected so that people can build interesting new things from it. At TED, Berners-Lee described Linked Data as boxes of data that - when connected via open standards - enable things to sprout from it.
Slide from Tim Berners-Lee's TED talk in Feb 09
Linked Data is one of the most important trends of the Web circa 2009 and we'll be blogging more about it in the coming months. Let us know in the comments if there's something specific you'd like us to explore in the Linked Data world.
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amazing, totally digg this. if italian government will open up to linked data, italy will be a better place.
just imagine other implementations, it's great.
Nice follow-up to my article, Richard! It is very important that everyone gets this awesome idea.
The other day I was wondering whether and when apps like, e.g., Wolfram Alpha will start using these knowledge bases. Up to date its knowledge bases on mostly encyclopedic and official sources (do a query and then hit "source information" at bottom) which have to be ingrated one after the other. To include a LOD source you only have to take of the vocabulary used there. The linking to further sources is a further plus!
I really enjoy this getting traction!
Cheers,
Alex
Agree with Federico. There is hidden big power in data held by governments.
Here in Latvia we have Central Statistical Bureau - part of government which collects and analyse data. Results are regularly published. But that’s already end result. If instead of that they would give access to structured raw data, it would be possible to make all kind of researches, create mash-ups with other data and etc. In economical down-turn such possibility would let people discover new opportunities, find new business niches.
At our own project - bonvoyagee.com we are developing rdf output for geographic places and related reviews. Also looking in foaf and other related standarts.
As the image from Tim Berners-Lee's TED Presentation is a citation of Hans Roslings introduction to Gapminders Trendalyzer (now a Google gadget), the obvious question comes to mind:
What metaphors of interaction or strategies for information presentation are out there, and how do they harness the semantics of the linked data "stack"?
That article might include things like the Google Wonder Wheel, Semantic Web Browsers and semantically augmented "related reading" widgets.
Put another way: How do people/companies innovate on top of this data?
TBL's presentation at TED was tremendously inspiring -- one of the clearest arguments for the potential of a "web of data" yet stated.
Apologies if this sounds too self-promotional, but I just posted my presentation for next month's Semantic Technology Conference on "data web marketing". It's an evolution of the thoughts discussed about year ago here on what the role of marketing might be in the semantic web.
If you're curious about one marketing-technologist's interpretation of TBL's vision, take a peek:
http://www.chiefmartec.com/2009/05/data-web-marketing-presentation.html
@Björn Have a look at Spimes...
Well, just like the buzz around Web 2.0 and semantic web, what nomenclature is put out for public consumption is unwieldy and dense to the point point of mystifying. As technical trade information, it is good strategic information, but has no traction until tools make it easy for programmers and data architects to get into production.
Even the Linked data industry's most ardent and eloquent evangelist, Kingsley Idehen of OpenLink Software, struggles mightily with building a conversation around RDF and Linked data. I applaud his messianic and thankless efforts.
Maybe Linked Data is a revolution. Maybe it will be completely transparent to the user, in a way that semantic web, that benighted 10+ years old basket of specification, is just becoming, no thanks to the pundits.
Björn,
There are several interesting semantic web browsers surfacing, take a look at razorbase and Parallax.
I've seen a lot of data represented like this lately! It's a great way to lay things out in a logical form wile still showing the relationships between items. Everything is connected in one way or another! Can't wait for this to become the norm!
Thanks for pulling this together for us!
@ATasteForTea
I think wrt linked data and exposing resources on the web, you should also include 2 other technologies:
OAuth, and the discovery protocol stack for URIs: LRDD
Writeup on LRDD:
http://www.hueniverse.com/hueniverse/2009/03/the-discovery-protocol-stack.html
My blog article on The Data Ecology, talking about discovery and the linked data ecology:
http://jpatterson.floe.tv/index.php/2009/04/19/the-data-ecology/
Anyway, I don't think we can see a "stable" linked data system until 2011. But this is the best period to dream about it.
Right on - The web has morphed into a huge ‘small world network’, connecting services, applications, people, places, ideas and knowledge in unforeseen ways. Adam Smith once spoke about “The invisible hand that guides the market.” The Internet’s invisible hand is evolution, not the balance of demand and supply. I mentioned this in my blog on new order of the web: see http://tr.im/newweb
What metaphors of interaction or strategies for information presentation are out there, and how do they harness the semantics of the linked data "stack"?
Apologies if this sounds too self-promotional, but I just posted my presentation for next month's Semantic Technology Conference on "data web marketing". It's an evolution of the thoughts discussed about year ago here on what the role of marketing might be in the semantic web.
@Alan Wilensky
yes, Mr. Kingsley Idehen's efforts to promote linked data & rdf are just overwhelming.
Kingsley Idehen: keep up the good work. we are listening and learning.
thank you!
-mani
Seem more easier to look forward. don't know when that will linked
Tim Berners-Lee - an IT legend.
Rgds Vince
Linked data is indeed exploding on the web; though this is really just the "toe in the pond" moment. Tools such as Zitgist Viewer, OL Data Explorer are making it significantly easier to browse linked data sets, and much deeper analytic / discovery mechanisms are on the horizon. Companies are also hard at work on solutions to "RDF-ize" unstructured content, to further "bootstrap" the linked data cloud. A brave new world, indeed!
@Sherman: Thanks for pointing out Parallax. Really like the concept, hope it will span more than one data source. But from the last time I saw this, there doesn't seem to be much improvement or evolution.
If you could make the User Experience on razorbase similar to that, it would really rock.
headup might be another inspiration for such interface improvements.
But to my mind, the real problem is in the difference between conceptual evaluation and monetization: Zitgist seems to be another victim of the do-it-all-approach. Good ideas, lack of focus, stagnating "product".
I guess razorbase is only a side project of your company?
Would be great if you could point us to an article about your overall semantic web strategy. Maybe titled "Monetizing the Linked Data Stack" ? ;-)
Thanks
Very good introduction from TBL! And great that he is promoting OpenStreetMap. Funnily enough however, he didn't link the data in the OSM demo.
Having kept a close eye on this space and tested a lot of these waters in the last 18 months i can indeed say that there is heavy growth in the amount of open datasets available, though this growth is occuring in a very decentralized way.
My startup Ranker has tapped deep into the linked data well, with a different approach than the other sites mentioned. we've just started a closed beta and hope to open the site up very soon. email registration at ranker dot com if you want an invite.
I would like to read more about where the value is captured in these open linked data ecosystems, in terms of business opportunities?
For data providers it's hard to monetize their openness, in case of governments the money is coming from tax payers which is fair in a holistic economical perspective. Paid APIs, value-added services, SLAs / quality or trust agreements, paid premium services on top of LOD,...?
Thanks for the post.
Linked data will be great for improving economies of scale in terms of data collection and maintenance for organisations. This technology will help prevent duplicate records, make databases cleaner and more accurate by using shared data. However, Iâm not sure if sharing this data across multiple networks breaches individualsâ privacy in terms of transferring and storing of their data. Would like to know more about how privacy is preserved with the linked data project.
Linked data is definitely the future of the web... but is it just "linking the roots of knowledge"? I mean, didn't we learn from the Web 2.0 that having users participate in the structure of knowledge (trough ranking, tagging, etc) creates massive amounts of emergent intelligence (del.icio.us, last.fm, etc)? Having knowledge linked "behind the scenes" and having mashups on top seems to me like it's missing something. How about if users actually created, classified, ranked and linked the entire knowledge? Lets allow users play with the roots of the "flowers". Not only we'll have much more evolved intelligence but we'll achieve higher forms of intelligence much faster.
I wrote an article about this topic recently and I called this new paradigm: Artificial Intelligence 2.0:
http://technotations.wordpress.com/2009/06/02/artificial-intelligence-2-0/
Leave some comments if you like this idea :-)
@Björn Re. monitization, your guess is as good as mines or anyone elses :) razorbase is just one of the many attempts to communicate the linked data/semantic web value proposition to laymen. There maybe a biz model there, but no, monitization is not a major concern right now for me. Thanks for the pointers re. interface improvement, all worth considering.
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This reminds me a lot of the video game industry where physics engines are all the rage. Build a physics engine and basically it's a game. Eventually, I hope that a modular format can be created that allows data to be labelled or categorized by proprietary methods but still automatically generate minimum keywords for base correlations.
I really do hate describing data. It's almost as bad as coming up with variable names, or names of kids, or pets.
We've gone from a Web of documents, via the WWW, to a Web of data. Berners-Lee is now on a crusade for everyone from government departments, to individuals, to open up their data and put it on the Web - so that others can link to it and use it.
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Linked data will be great for improving economies of scale in terms of data collection and maintenance for organisations.
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THank