Each month, Talis Inc CEO, Bernadette Hyland participates in The Semantic Link podcast series amongst other Semantic thought leaders. Paul Miller, the host of the series, introduces episode one and the “PodPanel” which includes: Peter Brown, currently Chair of the Board of Directors of standards body OASIS; Christine Connors, a consultant specialising in ontology and taxonomy design and related issues; Eric Franzon, Vice President of WebMediaBrands; Ivan Herman, Semantic Web Activity Lead for the World Wide Web Consortium (W3C); Eric Hoffer, Consultant and Andraz Tori, CTO of Zemanta. The second instalment is also now available.

Issue 12 of Nodalities is now available for download.

In this issue, some rather practical things that Linked Data is good at solving are being put to use saving lives: quite literally, as Bart van Leeuwen explains in our cover story. Simple ideas joining up public data and GIS devices are helping the Amsterdam fire service get their equipment to the scenes of fires more quickly and safely.

Elsewhere, Martin Belam, an information architect at the Guardian, tells us about their approach to Linked Data, and what it means to them. Talis’ Leigh Dodds outlines some of the challenge and opportunities of Linked Data in an evolving world in his article. Also supporting Linked Data research is the multi-organisational LATC Project which is introduced in this issue. And finally, Tim Hodson discusses a very practical approach to starting with Linked Data, and may also discuss eating an elephant.

You can subscribe to Nodalities for free here and read previous issues here.

I started the previous post in this mini-series with an assumption – ..working on the assumption that publishing this [local government spending] data is a good thing. That post attracted several comments, fortunately none challenging the assumption.   So learning from that experience I am going to start with another assumption in this post.  Publishing Local Authority data, such as local spending data, as ‘Linked Data’ is also a good thing.  Those new to this mini-series, check back to the previous post for my reasoning behind the assertion.

In this post I am going to be concentrating more on the How than the Why Bother. 

To help with this I am going to use, some of the excellent work that Stuart Harrison at Lichfield District Council has done in this area, as examples.  Take a look at the spending data part of their site: spending.lichfielddc.gov.uk/.   On the surface navigating your way around the site looking at council spend by type, subject, month, and supplier is the kind of experience a user would expect. Great for a website displaying information about a single council. 

However, it is more than a web site.  Inspection of the Download data tab shows that you can get your hands on the source data in csv format.  Here is one line, representing a line of expenditure, from that data:

"http://statistics.data.gov.uk/id/local-authority/41UD","Lichfield District Council","2010-04-06","7747","http://spending.lichfielddc.gov.uk/spend/8605670","120.00","BRISTOW & SUTOR","401","Revenue Collection","Supplies & Services","Bailiff Fees",""

… which represents the data displayed on this human readable page:

Looking through the csv, you can pick out the strings of characters for information such as the date, supplier name, department name etc.  In addition you can pick out a couple of URIs:

• http://statistics.data.gov.uk/id/local-authority/41UD – The UK Government identifier for Lichfield DC
• http://spending.lichfielddc.gov.uk/spend/8605670 –  Lichfield’s identifier for this payment

In the context of csv, that’s all these URIs are, identifiers.  However because they are http URIs you can click through to the address to get more information.  If you do that with your web browser you get a human readable representation of the data.  These sites also provide access to the same data, formatted in RDF, for use by developers.

You can see that data by adding ‘.rdf’ to the end of the address, thus: http://spending.lichfielddc.gov.uk/spend/8605670.rdf and then selecting the ‘view source’ option of your browser for the page of gobbledegook that you get back.  

Inspecting the RDF, you will see that most things, except descriptive labels and financial values, are are now identified as URIs such as http://spending.lichfielddc.gov.uk/subjective/bailiff-fees and http://spending.lichfielddc.gov.uk/invoice/7747.  Again if you follow those links, you will get a human readable representation of that resource, and the RDF behind it by adding a ‘.rdf’ suffix.

The eagle-eyed, inspecting the RDF-XML for Lichfield payment number 8605670, will have noticed a couple of things.  Firstly, a liberal sprinkling of elements with names like payment:expenditureCategory or payment:payment. These come from the Payments Ontology as published on data.gov.uk as the recommended way of encoding spending, and other payment associated data, in RDF.

Secondly, you may have spotted that there is no date, or supplier name or identifier.  That is because those pieces of information are attributes associated with a payment – invoice number 7747 in this case.

Zooming out from the data for a moment, and looking at the human readable form, you will see that most things, like spend type, invoice number, supplier name, are clickable links, which take you through to relevant information about those things – address details & payments for a supplier, all payments for a category etc.  This intuitive natural navigation style often comes as a positive consequence of thinking about data as a set of linked resources instead of the traditional rows & columns that we are used to.  Another great example of this effect can be found on a site such as the BBC Wildlife Finder.  That is not to say that you could not have created such a site without even considering Linked Data, of course you could.  However, data modelled as a set of linked resources almost self-describes the ideal navigation paths for a user interface to display it to a human.

The Linked Data practice of modelling data, such as spending data, as a set of linked resources and identifying those resources with URIs [which if looked up will provide information about that resource] is equally applicable to those outside of an individual authority.  By being able to consume that data, whilst understanding the relationships within it and having confidence in the authority and persistence of the identifiers within it, a developer can approach the task of aggregating, comparing, and using that data in their applications more easily.

So, how do I (as a local authority) get my data from its raw flat csv format, in to RDF with suitable URIs and produce a site like Lichfield’s?  The simple answer is that you may not have to – others may help you do some, if not all, of it.   With help from organisations such as esd-toolkit, OpenlyLocal, SpotlightOnSpend, and with projects such as the xSpend project we are working on with LGID, many of the conversion [from csv], data formatting processes, and aggregation are being addressed – maybe not as quickly or completely as we would like, but they are.  As to a human readable web view of your data, you may be able to copy Stuart by taking up the offer of a free Talis Platform Store and then running your own web server with his code that he hopes to share as open source.  Alternatively it might be worth waiting for others to aggregate your data and provide a way for your citizens to view your data.

As easy as that then! – Well not quite, there are some issues about URI naming and creation, and how you bring the data together that still do need addressing by those engaged in this.  But that is for Part 3….

National Government instructing the 300+ UK Local Authorities to publish “New items of local government spending over £500 to be published on a council-by-council basis from January 2011” has had the proponents of both open, and closed, data excited over the last few months.  For this mini series of posts I am working on the assumption that publishing this data is a good thing, because I want to move on and assert that [when publishing] one format/method to make this data available should be Linked Data.

This immediately brings me to the Why Bother? bit. This itself breaks in to two connected questions – Why bother publishing any local authority data as Linked Data? and Why bother using the, unexciting simplistic, spending data as a a place to start? 

I believe that spending data is a great place to start, both for publishing local government data and for making such data linked.  Someone at national level was quite astute choosing spending as a starting point.  To comply with the instruction all an authority has to do is produce a file containing five basic elements for each payment transaction: An Id, a date, a category,  a payee, and an amount.  At a very basic level it is very easy to measure if an authority has done that or not.

Guidance from data.gov.uk expands on this a little by mandating the following:

… a little more onerous, possibly around the areas of identifying company numbers and Service Categorization, but not much room for discussion/interpretation.

As to the file formats to publish data, the same advice mandates: The files are to be published in CSV file format - supplemented by – Authorities may wish to publish the data in additional formats as well as the CSV files (e.g. linked data, XML, or PDFs for casual browsers). There is no reason why they should not do this, but this is not a substitute for the CSV files.

So fairy clear, and measurable, then. You either have published your required basic elements of data in a CSV format file, or you have not.  Couple this with the political ambitions and drive behind the Government’s Transparency Agenda, and local authorities will have difficulty in not delivering this.  Although some are being a bit tardy and others seem reticent to publish in formats other than pdf.

OK so why bother with applying Linked Data techniques to this [boring] spending data?  Well, precisely because it is simple data, it is comparatively easy to do, and because everybody is publishing this data the benefits of linking should soon become apparent.   Linked Data is all about identifying things and concepts, giving them a globally addressable identifiers (URIs) and then describing the relationships between them.  

For those new to Linked Data, the use of URIs as identifiers often causes confusion.   A URI, such as  http://statistics.data.gov.uk/id/local-authority-district/00CN, is a string of characters that is as much an identifier as the payroll number on your pay-check, or a barcode on a can of beans.  It has couple of attributes that make it different from traditional identifiers.  Firstly, the first part of it is created from the Internet domain name of the organisation that publish the identifier.  This means that it can be globally unique. Theoretically you could have the same payroll number as the the barcode number on my can of beans – adding the domain avoids any possibility of confusion.  Secondly, because the domain is prefixed by http:// it gives the publisher the ability to provide information about the thing identified, using well established web technologies.  In this particular example, http://statistics.data.gov.uk/id/local-authority-district/00CN is the identifier for Birmingham City Council, if you click on it [using it as an internet address] data.gov.uk will supply you information about it – name, location, type of authority etc.

Following this approach, creating URI identifiers for suppliers, categories, and individual payments and defining the relationships between them using the Payments Ontology (more on this when I come on to the How)  leads to a Linked Data representation of the data.  In technical terms a comparatively easy step using scripts etc.

By publishing Linked Spending Data and loading it in to a Linked Data store, as Lichfield DC have done, it becomes possible to query it, to identifies things like all payments for a supplier; or suppliers for a category, etc.

If you then load data for several authorities in to an aggregate store, as we are doing in partnership with LGID, those queries can identify patterns or comparisons across authorities.  Which brings me to ….

Why bother publishing any local authority data as Linked Data?  Publishing as Linked Data enables an authority’s data to be meshed with data from other authorities and other sources such as national government.  For example, the data held at statistics.data.gov.uk includes which county an authority is located within.  By using that data as part of a query, it would for instance be possible to identify the total spend, by category, for all authorities in a county such as the West Midlands.  

As more authority data sets are published, sharing the same identifiers for authority category etc., they will naturally link together, enabling the natural navigation of the information between council departments, services, costs, suppliers, etc.  Once this step has been taken and the dust settles a bit, this foundation of linked data should become an open data  platform for innovating development and the publishing of other data that will link in with this basic but important financial data.

There are however some more technical issues, URI naming, aggregation, etc.,  to be overcome or at least addressed in the short term to get us to that foundation.  I will cover these in part 2 of this series.

Towards the end of 2010, Wikileaks generates many headlines as it publishes information on the web, causing controversy and leading to talk about politicians hiding information from the public. Reporters and commentators express shock or admiration when telling the story of a rogue organisation making governmental information public. What has not been as mainstream is that for the past year or more, governments around the world have been doing something very similar themselves: publishing information online.

Big names like President Obama, Sir Tim Berners-Lee and the headliners at big events like the International Open Government Data Conference favour publishing public data for transparency and benefits to society. This all finally began to take off in 2010. Governments from around the world have been developing their public information strategies, with the launches of data.gov and data.gov.uk and data.govt.nz.

This is all taking place at a time of economic restraint. Dr Martin Read from the UK Cabinet Office’s Efficiency Reform Board explained in a recent interview: “If you are going to improve the efficiency of something, making that change involves risk and innovation  … If they get it wrong, they’re hauled up in front of a committee for interrogation.” (moderngov, November 2010) It may seem tricky to justify the expense of big projects like data.gov.uk, and there certainly seems to be a huge amount of pressure.

Nevertheless, governments are proving themselves committed to prioritising data publishing. Towards the end of last year, the UK Prime Minister announced that every item of governmental spending over £25,000 will be published online, and updated monthly. He emphasised the importance of this publication in terms of transparency, inviting the public to scrutinise the data. Interestingly, he also said: “This scrutiny will act as a powerful straightjacket on spending, saving us a lot of money.” So, not only is data publishing seen as a benefit to democracy, but also as a useful way to “flag up waste”.

While that press conference was taking place, developers and civil servants were gathered together elsewhere at the Open Government Data Camp (disclosure, Talis was a sponsor). At the event, much was made of the modelling and tools which have been developed with open data in mind: particularly the Linked Data API, which allows developers from just about any web background to work with data.gov.uk’s data very quickly. Visualisations demonstrated what can be done with well-structured data.

One of the things this high-level data publishing has done is raise the standard for what can be published and developed. Last year, we built a proof-of-concept app for the Department of Business Innovation and Skills (BIS) to illustrate the potential of applications of this data. A few minutes spent on DEFRA’s UK Climate Projections site shows what can happen when raw data is matched with a plan, and is designed with a citizen in mind. Anyone can check the primary source for their government’s climate policy, and it doesn’t take a climatologist to understand it. A little further development allows fully-fledged applications to be built that are instantly useful: one available on the front page of data.gov.uk lets me download an app that helps me plan my cycle route!

Open government data is probably good for transparency. But it’s also got a plenty of potential to seed ideas that add value to this information. Innovators know that there are more people with better ideas outside our organisations than could possibly be in them, so sharing means that they can be developed into products and services that are mutually beneficial to everyone. The web industry routinely works with open-source software that’s been at least partly built by others, and this open-source mentality might just be an incredibly useful piece in the public-sector machinery. Open business models work very well with ideas.

2011 promises to be the year when all this data gets put to use. I was recently invited to a press conference at which the Deputy Prime Minister confirmed the UK’s commitment to published data as a priority and even a recognised civil liberty. The story will shift to more local applications of big public data tools. January will see the publication of local authority’s spending data, and public bodies will be looking to add value to this data, bringing the headlines of open data to life in the places we live.

With a bit of thought into how data is published in the first place, and a plan for encouraging people with good ideas to work with this information, this investment in data publishing could be more than just a tick-box exercise for a political transparency agenda. I hope that this year, it won’t be Wikileaks-level events that get people talking about open data publishing. We should notice it improving services we use, and see whole new applications for the bits and pieces of information that make up our public lives.

Talis is delighted to be one of the sponsors of the 8th European summer School on Ontological Engineering and the Semantic Web (SSSW 2011). There will be more about this in coming posts, but just to start off:

We are sponsoring it for a very simple reason. The mix of theoretical, practical and collaboration skills used by all the students involved from across Europe directly corresponds to how we work at Talis. It’s an environment of support and challenge, contribution and connection that has proved beneficial for all involved over the years. Talis is proud to contribute and participate to further the aims of the community.

Talis is a small and ambitious company of likeminded, motivated people. A phrase we often use here is Human Scale. Culturally what we mean by that is we like working closely with people who we all know, whether as employees of Talis or (more likely) over time collaborating as partners in joint endeavours.

We want to grow our company and contribute to the communities we belong to. We know that it is by fostering relationships with others driven by the same passion to collaborate and learn that we can build on the ambitions we have for ourselves and for the communities we belong to. One particular aspect of the Summer School is this same notion of social connectedness, a personal network of trusted relationships that challenge and enhance the experience for everyone.

“Free citizens must be able to hold big institutions and powerful individuals to account.”

I attended a speech at the Institute for Government by UK Deputy Prime Minister Nick Clegg at which he outlined the government’s stance on civil liberties. This topic is one I am particularly passionate about as a citizen of two democracies, and as a lover of history and human communication, but what was there to interest a software evangelist?

Mr Clegg’s speech is available as a transcript from his party’s site, so you can have a look at the same words I heard. If you read through a lot of the political positioning (references to “Labour”, for non-UK readers, refer to the majority party of the previous government), you get to the bit that interests me as a Talisian as well as a human.

The final point talks about citizens having the right to public information, and the right to speak out about what government (and, notably, publicly-subsidised industry) is doing. The freedom of information and freedom of speech are under the same heading. As Clegg put it:

“It is a modern right to information combined with traditional freedom of expression.”

Examples are given of current transparency measures, including the publishing of particular datasets that are already being used in innovative ways and to hold the government accountable. It’s clear from the speech that transparency is a priority, and that publishing data is seen as fundamental to this.

The theme of balancing security and freedom is repeated throughout the talk, alluding to the fact that some information in any government is clearly going to be kept secret. But the emphasis is on publishing wherever possible, and it was interesting that this felt like the most specific theme of an otherwise very high-level speech. This is an area of public policy that has been changing through the launch of data.gov.uk and the continued efforts of two successive governments (and, interestingly, all three major UK parties) to put public data online. The idea that these datasets will be used, reused, mashed up and seed innovation is at the forefront of these talks. This isn’t just data that can be seen, it’s data that can be used.

So, this government seems committed to continuing the trend for transparency through public information, and for their data to be made available online and in useful ways. The emphasis in this speech, however, adds a new dimension to the commitment, at least the way I understand it. It’s not just that data is a right of any free citizen—the Prime Minister said as much before he was PM—but that this right goes hand-in-hand with the citizen’s right to free speech.

Government publishing its data online, free to reuse and feed applications that make it easier to interact with the information has been a huge step. Alongside this is the area of libel reform, which is a topic too big to get into here but involves the scrutiny of scientific and journalistic investigation without the fear of prosecution. (Guardian journalist Simon Singh discusses libel reform here.)

Although Mr Clegg’s talk is mostly general, discussing big ideas and leaving out specifics, I think the principles discussed were hugely important, and it is good to see a further commitment to public data. As a Talisian, it’s great because we work a lot with this kind of data, and it means we get to do more interesting things with it. As a citizen, it’s important that we can see more of what’s going on within government and that it is being considered fundamental enough to mention alongside freedom of speech and libel reform encourages me.

What I’d like to see this year is the specifics, now. What specific things will make publishing public data easier and more thorough?

A colleague sharing their experience of visiting Ironbridge, promoted as “The Birthplace of the Industrial Revolution” helped clarify some thoughts I have been brewing to help convey where the current Linked Data enthusiasms and initiatives may lead us.

The famous Iron Bridge, opened in 1781, spans the River Severn in Shropshire, England.  To quote the Wikipedia “It was the first arch bridge in the world to be made out of cast iron, a material which was previously far too expensive to use for large structures. However, a new blast furnace nearby lowered the cost and so encouraged local engineers and architects to solve a long-standing problem of a crossing over the river.“  The raw materials of iron ore and coal had been known for a long time, but it took the building of a nearby furnace, using the innovation of coke as a fuel, that enabled the local community to invest in the construction.  The outcome was not only to stimulate the local commercial and administrative economy, but it also became an 18th century tourist attraction, which it continues to be today.

All very interesting, but what has this to do with Linked Data and it’s future?

The impact of Linked Data and the Web of Data it enables, on the way we interact and do business, will be greater than that of the World Wide Web that it builds upon.

When one makes statements like that one, you are often asked to justify yourself.  As you may know, I like to use analogies to help clarify things and I believe the Industrial Revolution is a good one in the case of the future for Linked Data and associated techniques.  I am also very aware that analogies tend to fall apart if you pick at the detail too much, so please bear with me on this one.

Like the Industrial Revolution, Linked Data is building on what went before.  Before the Iron Bridge, there were other bridges, roads, and uses of iron.  Before Linked data there was/is the Web – a globally distributed web of linked human-readable web pages, upon which are surfaced words and images for our information, entertainment and commercial desires.  Data of course plays it’s part, often powering the websites that we all consume.

So what is so special about a Web of Data? – The data comes out from behind  those websites to be linked with other data across the web, or maybe an intranet.  Using the same techniques for linking pages together [the URL], data identifiers are given URIs.  This means that a piece of data is given an identifier that is addressable across the web and therefore linkable with other data identified in a similar way.

So where does the Industrial Revolution analogy kick in?  Well, once data are identifiable in a globally distributed context, they can be linked, mixed, mashed, and generally used to add value to each other.  Your data can become the raw material for someone else’s process – your Wikipedia comment about an animal can become the description on a, data powered, BBC page about that species.  As with coal, which after some refinement can become coke to be used to add value to the iron smelting process, any published data can be the raw material for value adding/combining processes.  The processor, utilising their knowledge, skills, and experience to produce an alloy of data, the combination of which is greater than the sum of it’s parts.

In the same way that some freely available elements, such as the air pumped in to that blast furnace, were needed to get the process going; freely and openly available data, such as governments and the media are publishing, are priming the pumps of a data revolution.

Whenever there is value to be added in a process there is both community and commercial opportunity.  Once people start using their skill and understanding of a facet of knowledge, to link data from one free, or commercial, source with more free or commercial data they can produce either a saleable result, and/or an enhancement to their own services.  The output of one value-add process can then become one of the sources for yet another, and so on.

To finally stretch my analogy just a little further – looking back to those early days in the Severn Valley, it is possible to identify the building-blocks that led to commercial steel production, the age of steam, the automobile industry, and space flight.  Most of which would have been unthinkable by those early pioneers.  Pre-1994, could we have predicted the growth of Google, YouTube, Wikipeadia, and Twitter?  In 2010 can we identify the building-blocks of a data revolution?  – I think maybe we can.

So how will such a revolution, underpinned by Linked Data, change the way we interact and do business, more fundamentally than the Web has? -  By creating whole new communities and industries to connect, supply, trade, enhance, distribute, interpret, and build services and applications upon a supporting web of globally available data elements and alloys.

I presented What place for libraries in a Linked Data world? at Online Information in London on Wednesday 1st December. The slides are available on Slideshare, but I’ve now recorded some accompanying audio to enable those who weren’t at that event to make better sense of the presentation. In considering the question what place for libraries in a Linked Data world? I have embedded some preliminary research on the applicability of a Linked Data approach to intertextual relationships between literary works. I hope to research this area further, but related to the question at hand, it fits in nicely as a case study.

<h2>What place for libraries in a Linked Data world?</h2>
 

Yesterday I gave a short talk at Online Information 2010 titled “Challenges and Opportunities for Linked Data” (abstract). The presentation highlighted what I saw as the main challenges that face us as we grow the web of data, and highlighted some opportunities for organisations that want to get involved.

I believe there will be video from the various presentations online at some point, but wanted to post a transcript of what I said (or had planned to say!). The slides are up on slideshare if you’re interested, although they’re largely just transitions to highlight my main themes.

Introduction

2010 has certainly been the year of Linked Data. I’ve been working with RDF and Semantic web technologies for about 10 years now, and its clear that the last 12 months have been one of the critical growth points for Linked Data and the semantic web as a whole. There has been more debate, engagement, and publication of data over than ever before.

This is in no small part due to the fantastic work that has taken place at data.gov.uk. The project has not only championed the approach but also lead the way as an exemplar for how to do this stuff really well. The adoption of RDFa by Facebook, Google and others has also created a much needed feedback loop that is driving the publication of more structured data.

But as the technology grows we’re starting to experience growing pains which are presenting challenges for further growth and adoption. I think we’re also getting a sense of the opportunities that may arise from the web of data. I picked out three key challenges to review in the presentation.

Craft

The first of these relates to what I’d call “the craft” of Linked Data. To date the growth of the Linked Data cloud has largely been driven by skilled artisans — from academia and a small number of commercial organisations — who know how to work with the technology, how to use and manipulate the data that is already available, and how to get things online and linked together in a way that achieves the 5 star approach.

To scale beyond the initial Linked Data community we need to move from an artisan lead approach and enable “journeyman” developers to achieve the same things. There are several facets to this skills transfer.

Tooling is clearly one important area. It’s a truism that Linked Data tools aren’t as polished as they might be. After all it’s still a relatively new technology area. The majority of Linked Data artisans have been happy enough either to make their own tools or to work with a disparate selection of tools to get the job done. But there is still a lot more work to do in creating a more integrated toolkit that journeyman developers can reach into to help them quickly and easily publish data.

To be fair though, I think we’ve needed these past few years of publishing and experimentation to really highlight what those basic tools might be.

The other aspect of craft is education and training. There’s still a relatively small community with deep skills in this area, so thought has to be given to the ability to transition wider. Having helped train and advise a number of team and organisations over the past few years, most recently as part of our consulting work at Talis, its clear that there’s a journey or apprenticeship that many teams and organisations undertake as they begin to experiment and gain experience with the technology.

Within the Linked Data community we need to prioritise the work on these tools and services to make it easier for others. We also need to devote additional work to help nuture or define more standard vocabularies for publishing specific types of data. In my opinion this is the real challenging work: it’s not as fun or exciting as publishing the next new dataset or exemplar, but it’s absolutely necessary to push things to the next level. It’s going to take real commitment from all of us.

In my mind there is no better way to help pass on the skills of the initial artisan community than by encoding that knowledge in the form of tools, vocabularies, best practices and design patterns.

Fuelling Applications

Linked Data isn’t being used as much as it could or should be. Why is this?

I think there are two reasons. The first relates to my previous point about enabling the “journeyman” developer. Right now it takes a certain amount of skill to get the most from Linked Data and SPARQL. This presents a road-block for developers who may be interested in using some of the available data. It may even stop them looking at all.

To solve this we must be ready to meet people half-way. Publish simple JSON formats alongside the RDF. Use the Linked Data API created for data.gov.uk to provide simple RESTful APIs into your RDF data. Choice opens up more integration opportunities as well as encouraging engagement. The power of SPARQL and other tools is fantastic, but that power is not needed by every developer in every application. Be inclusive when opening up data.

A potentially larger issue is that much of the data available as Linked Data is either static, irregularly updated, or already available in other more accessible formats and APIs. This isn’t true across the cloud as a whole, but timeliness is an issue in many areas. It’s a consequence of the early boot-strapping process which emphasised conversions of available data dumps, and the wrapping of existing APIs and services. As a boot-strapping process that has been fantastic. But it’s not driving engagement: why use data if you can get it somewhere else easier, and in a more up to date form, using tools that you’re already familiar with?

I also think that this is contributes to the reason why it has been difficult to show the power of Linked Data: many of the demonstration apps could easily have been built with other APIs. I think this could be on the cusp of changing as there is now a critical mass of information available to do some powerful queries, and an increasing amount of data is now becoming primarily available as Linked Data.

The challenge we face is changing the nature of the Linked Data cloud from what is a largely static and slow moving environment to one that is much more lively and real-time.

Sustainability

The third challenge I highlighed was sustainability. It’s easy to look at the Linked Data diagram and think: “Well, those bits are done, all we need to do is look how to grow the diagram. We just need to add more data”. I think that’s a natural but unfortunately misleading viewpoint: we need to look carefully at our foundations.

Not all of these sources are on infrastructure that could support real, high volume usage. And few of the datasets are clearly licensed. I’ve personally encountered a number of occasions where some significant datasets are offline or unavailable. So we need to be realistic about whether people can build a stable, commercial application against the web of data as it exists today.

Again to solve this, we need an increasing number of primary sources, making high quality data available on a regular and timely basis, backed by the ability or commitment to deliver those services at the scale we will all eventually require.

In reality this challenge isn’t unique to Linked Data. It’s largely true of the web as a whole; after all not every web site or application is intended to scale to high volume usage. But we’re now talking about a potentially much deeper integration between different applications. We can see the same issues occuring around APIs and data access in general. In recent months there have been a number of stories of developers scrabbling to adapt as APIs get changed, taken down, restricted or re-licensed leaving them high and dry.

To me the beauty of Linked Data, and RDF specifically, in this regard is that it is so much more portable than any other format. This means that we can easily replicate data to share the load of providing access. With Linked Data we have the option of federating or sharing data across the web. (One of the reasons we started the Talis Connected Commons scheme was to help create sustainability around Public Domain datasets.)

The portability of RDF also makes it easier for a range of organisations to offer scaleable value-added services over the same datasets. For the first time we can decouple the curation of data from the delivery of services over that data.

So those are my three challenges. I think these are largely point in time issues, but we’re going to have to work at them to move forward.

What about the opportunities?

Become a Hub

One of the interesting properties of the Linked Data cloud diagram is how it clearly illustrates the emergence of a number of hubs — like dbpedia — that form the focal points for links from a number of different datasets. If you look closely you can also see that there are emerging hubs within specific subject domains.

I wonder whether the hubs that we see today will continue to play such a key role as the web of data evolves? My feeling is that in a few years time the picture and connectivity is going to be quite different. Particularly if we continue to see engagement from government and other sectors.

There is clearly an opportunity here for organisations who are already key enablers within a particular sector to become a linking hub on the web of data.

If you poke around in any industry, its not hard to find organisations who act as the “switchboard” for that particular sector. Either because they manage some key identifiers for the sector as a whole, or because their identifiers and systems have become de facto standards for achieving interoperability. It would be a natural step for those organisations to carry that role forward to the web of data, retaining that key position.

Clearly not everyone can be a significant hub like Dbpedia. But every organisation can act as a hub for its community of customers, partners and users.

The reasons and benefits for doing this are well documented: opening up data can drive new business, innovation, and traffic. Success on the web involves giving your organisation the greatest possible surface area and points of attachment. Linked Data is an excellent way to achieve this as to emphasises the right forms of web integration.

Turn Identifiers into Channels

Linked Data requires you to assign URLs to identify things: people, places, events, whatever. Generally we tend to focus on how that is an important step to publishing data: concentrating on the mechanics of what makes a good, stable identifier and highlighting how this becomes a key way for other people to find your data.

What this misses is that those identifiers can also become channels, or hooks, for your organisation to find other people’s data. Once you have published Linked Data and it becomes linked to by other datasets all of that external data annotates and enriches your own, providing valuable and useful context. Linking data creates network effects, and everyone in the network benefits. That includes you.

The external data is easily accessible through link discovery so it becomes much easier to find, aggregate and analyse it for a variety of purposes. That might be to drive new product features, or to simply power business intelligence and analysis within the enterprise.

I tend to think of it as being able to fish the web of data for useful context. Your URIs are the hooks. Your data is the bait.

I stopped to draw a parallel here with some comments made by Dion Hinchliffe in his opening keynote. Hinchcliffe pointed to the rise of a number of startups and tools supporting analysis of data collected from the open web, perhaps mixed with data from internal enterprise systems. The end results of that analysis is new data and insights that will need to be integrated into an organisations core systems, especially if the intent is to drive more than just management reports.

My prediction was that over the next 12-24 months we’ll begin seeing this type of third-party organisations not just offering SaaS access to analysis systems, but direct insights that are already integrated into a customer’s data via the public identifiers its sharing as Linked Data. This has huge potential value and can completely change the costs and approach to data integration.

The time scales may be completely off. But there’s a real opportunity there in my opinion, particularly for organisations that do market and social media analysis.

Data as a Service

It’s been said before but its worth repeating: Linked Data isn’t necessarily Open Data. The technology is not at odds with exploring business models around data services or access.

The “Data as a Service” (DaaS) idea is gaining momentum in a number of different areas with an increasing number of commercial APIs coming online. We should also soon be seeing commercially available services directly powered by open data sources or through mining those sources.

There are a number of different business models that can be wrapped around data access, ranging from charging for the data itself, through cost recovery for service provision — something that may be relevant for long term usage of government sources — or just charging for delivering reliable, high performance services over open data. There are good reasons why developers may want to pay for reliable services.

Clearly open, sponsored access to data and services will remain an important part of the ecosystem. In fact some level of open data is required to drive the network effects we are seeing around Linked Data: the identifiers and some key metadata needs to be open and remain open; but additional “depth” could be available at a premium.

Summing up

I had no big conclusions to draw from my talk as my goal was to highlight the challenges and opportunities ahead. Clearly I could have chosen a different mix but drawing on my recent experiences engaging with a wide range of different organisations these are the issues and opportunities I’ve most commonly encountered and discussed.

Do you have a different perspective? Perhaps some ideas about how to face these challenges, or a different view of the immediate opportunities? If so, I’d love to hear from you.