I’ve been trying to consider how to make open linked data websites more friendly to consumers of data. With the specific example of data provided by an organisation or by an event. Such data has value as part of the greater scheme, but a key value is going to be for people dealing with specific immediate questions.

It is my strong belief that providing open linked data in standard patterns will make it easier to consume. This will increase the number of consumers and this, in turn, will increase the value of producing open and linked data. Self interest is a much better motivator than altruism!

With this in mind I suggest defining certain RDF classes which indicate that a resource of that class follows a certain pattern.

Aspects of a Pattern

What a pattern consists of can and should vary wildly, but could include;

• What format data is available if you resolve the URI with different client “accept” headers.
• What information will be available in the RDF document you get when you resolve the URI, and using what namespaces.
• How to discover an endpoint to query the data via SPARQL (or OAIPMH2, or even some REST interface etc.)
• How to efficiently download all relevant data pertaining to this thing.
• What sub patterns apply to URIs referenced in the data available from the main URI.
• What structure related URIs will take.

Obviously, if rolling your own data from scratch you won’t always fit into a very specific pattern, but you may still be building large parts of it using a standard pattern. For example, foaf:PersonalProfileDocument already does this. It tells you that this document can be resolved as RDF and tells you foaf facts about a person.

An oddity is that owl:sameAs does not transfer a pattern to the same-as URI as it almost certainly will provide data in a different pattern. That’s kinda the point.

EPrints as an Example

An EPrints repository may serve many purposes. The most common is as a repository of the research output of an organisation, but it could just as easily hold teaching and learning materials or a repository of software.The open linked data about each of these can tell us that they are all datasets, which isn’t that all that useful. We could add some classes to describe the content of each, for example <http://files.eprints.org/id/repository> rdf:type myns:SoftwareRepository . This is all very well, but it doesn’t help a tool consume the data. To help systems understand how to navigate and consume data in an EPrints repository, the top level URI is defined as of rdf:type eprints:Repository which defines the entire way that an EPrints repository publishes open linked data. That way a tool build to work with repositories can see this RDF class and know what to expect. Maybe D-Space would define their own. That way some simple tweaks and you could build an application which could work with the majority of repositories and auto adjust behaviour to paper over the cracks between them.

See our freshly defined EPrints open linked data ontology — note we use bibo, dublincore and voiD to describe most of the data in the dataset, the EPrints classes and relations are only used to describe the native structure of the data.

Doesn’t this happen already?

Well, maybe unofficially. What I’m keen to do is get people attaching specific to such classes and keeping them separate from classes which represent what the resource is. It may be that some people would prefer to link these with a different predicate to rdf:type. Maybe implementsPattern?

One reason it hasn’t happened much yet is that there’s not that many packages which pump out linked data. There’s a few plugins for things like WordPress, but they are not yet mainstream. EPrints 3.2.1 automatically supplies linked data in a reasonable pattern  with minimal work from the site admin. This means there will be a proliferation of sites offering open data in a very similar structure. A reasonable solution is just to identify that it’s in the pattern as produced by that tool. That’s what we’re doing at EPrints. A better long-term solution will be when people start defining generic patterns.

Where this starts to get interesting

So, I’ve been considering how we might deal with the complexity of open linked data for an entire university (I’m still growing that map, contributions welcome). At a basic level, what we’ve discussed is having a top level index of other datasets. What I would like to aim for is that people could write tools which can find the primary URI for an organisation and find what elements of open data are available, or if the standard element they want is auto-discoverable.

Let me walk you through a scenario. I’m going to a seminar in Building X1 of Example University. I’ve already installed a phone app which helps me navigate open linked data for organisations. The app. understands many standard patterns of data organisations provide.

It is also preloaded with the fact that <http://data.ac.uk/resources/universities.rdf> can be resolved to get a list of basic information about UK universities. In this case we want the  primary, and resolvable URI for Example university, but it also contains a list of homepages, .ac.uk domains, foaf:located_near to the nearest major city, the data.gov.uk URI for the university and a few more handy facts to hold at the .ac.uk level. It also describes them all as of rdf:type jisc:University and many as somens:OpenOrgPattern which indicates we can resolve the URI as RDF and it will tell us some basic facts about the org,, and more usefully it will tell us what sub datasets are available indicated, where meaningful, by a set of standard rdf classes indicating both the semantic meaning of each sub-dataset and what pattern or patterns it is made available as.

Selecting the “UK Universities List” I can easily navigate to example university. It’s guessed it from typing “Exa”. The URI is <http://data.example.ac.uk/id/org/exampleuni>

Now the phone nips off and grabs (or uses a cached copy of) the RDF document describing Example University. This document isn’t too large. It tells us some basic foaf such as the name, homepage and primary phone numbers etc. It also defines a whole bunch of hasDataset relations to a variety of datasets from key parts of the institution. Each of these has an rdfs:label, at least one rdf:type indicating its content and usually one indicating what pattern the dataset implements.

For example;

 <http://dspace.example.ac.uk/#dataset>
   rdf:type <http://dspace.com/ns/DSpaceRepository> ;    
   rdf:type myns:ResearchRepository 
   rdfs:label "Example University Research Repository" .

Maybe there’s more data about voID and licenses which isn’t a required part of the OpenOrgPattern. If so my phone doesn’t currently understand it so we ignore it. My phone has discovered a dataset of type myns:OpenBuildingsPattern and is going to follow that. From there it can understand how to find a list of the names of all buildings, and easily find my the lat & long of building X1 and show it on a map. It’s spotted another standard dataset it undestands that’s part of the RDF returned by http://data.example.ac.uk/id/org/exampleuni and that’s myns:PublicTransport which lists locations of relevant transport nodes such as bus-stops train stations and taxi ranks etc. and adds the nearest ones to the map it’s showing me, along with nearby public carparks it found in the OpenBuildingsPattern.

To make all this awesomeness happen, all that’s needed is to start converging on some standard patterns and give software clues of how to consume it.

— Chistopher Gutteridge

Many of us will have seen the Linking Open Data cloud diagram, which shows which datasets are linked to each other.

This is great for showing the rough state of the web of linked data, and seeing how it changes over time.

As a developer though, it’s of less use. It serves as a guide to which identifiers for a subject might be good to use (e.g. lot of datasets link to DBpedia, it might be wise to refer to that rather than creating our own URIs for things), but doesn’t really say how that data is being used.

I’ve been thinking about how to best show this for the growing area of University linked data. As someone working on University linked data, I want to know what other Universities are using and how. I want to know what best practice should be for describing the same concepts.

At this stage, it seems unlikely that many institutions will have data that links to other institutions – most institutions will initially just have (and be making available as linked data I hope!) data about themselves.

It therefore seems more important to me that institutions talk about things in the same way, rather than necessarily talking about the same things.

This basically comes down to using the same ontologies to describe things – if a dozen Universities all describe their people using FOAF for example, that’s a great start. People can start building common tools/applications/aggregators based on this, without having to reinvent the wheel to deal with University X’s custom data structures.

I’m not great at visualisation, but I’ve started putting together a simple diagram to indicate some of the things that some Universities have made available as linked data, and more importantly, the ontologies they’re using:

(view full size)

As you can see, it’s pretty small/limited at the moment, and the only University data sets I know about are our own, Sheffield’s, and the Open University’s.

Additions welcome! I’ll aim to keep the diagram updated as much as is feasible – any suggestions on a better visualisation for this would also be welcome. I’m hoping once we’ve got a few more institutions on board, it’ll be a useful starting point for University linked data developers to see which vocabularies are most commonly in use.

Dave Challis
dsc@ecs.soton.ac.uk

Ben O’Steen, gentleman library hacker, just sent us this rather awesome portrait of The Modeller.

I’m tempted to upload it to cafepress…

I am a regular reader of the Blog written by Tony Hirst at the Open University. He’s always looking for existing tools which can solve new problems. I think my thing is looking for little tools which don’t exist but should.

I’ve had an idea for a while that it would be cool to use RDF to add data into a webpage, but there’s no easy way to do it. So what I’ve done is a combination of a web service and a javascript library.

Here’s how to use it to take a URI of a location with a geo:lat and geo:long and embed a map in your webpage:

 <script src='injectgeo.js' type='text/javascript' ></script>

 <div id='mymap'></div>
 <script type='text/javascript'>
 injectGeo('http://dbpedia.org/resource/Brading','mymap');
 </script>

It would be only a little extra work to start using linked data goodness in the mix.

• See it in action!

Images in Linked Data

One interesting problem with the above page is the picture of TimBL is bloody huge. We don’t include size information in the FOAF data so it’s not possible to pick which size to show. Where last week I said we should aim to always include an rdf:type and one of the normal label attributes (dc:title, foaf:name, rdf:label etc.). I think I’m going to suggest that images should have a width and height. Anyone know some good predicates for that?

This is a week of beginnings and endings. The new freshers are arriving. But we are bidding farewell to two members of the ECS Web Team. Sarah Prendergast and Joe Price. Both have applied for and been accepted for the university voluntary severance scheme.

We’re very sorry to see them go, they are valued members of the team.

Joe is a skilled all round web designer and developer who is going to start his own small business. To anyone considering engaging him, let me say that he has been a pleasure to work with. His designs are always of a high standard and he has shown a level headed pragmatism – balancing innovation with good basic design and use of standards. He finishes what he starts and people are always happy with the result. (I figured it would save me responding to queries for references if he can just link to this blog post *grin*)

Sarah has also been a pleasure to work with, and her work can be seen throughout our publications, posters and websites. As a new mother and an enthusiastic equestrian I’m sure she’s going to find plenty to keep her busy for a while!

Planning for the Future

With the university being restructured there’s bound to be some change, but with Web Science and Linked Data on the ascent, there’s still plenty of interesting stuff to look forward to. What I have been doing for the last month is trying to plan how to manage with such a reduction in resources. That horrible phrase “more with less” is being spoken.

I understand why web design has taken the brunt of our staff reductions. While I am sad and frustrated, I can see that reducing the web team means fewer and less rich websites, but reducing the network, servers or email means things take longer to get fixed when they break. This has a very obvious cost compared to the very subtle cost of confusing and out of date websites.

My job now is to work out where to cut the services we provide. Joe has had some simple but excellent suggestions.

Triage

The key thing is to work out what we currently do in terms of costs and benefits. The only real cost to my team is time, servers and bandwidth are negligible compared to staff time. The place I think we can reduce our effort is in providing bespoke websites for projects and conferences. Historically we’ve done some great work,  but we just don’t have the slack to build awesome sites from scratch for things. Joe’s suggestion is to build up some standard site templates and use these to build project & event websites. We’ve already started this in a small scale by creating a standard template for projects, and also building sites with the intent of reusing the templates and back-end design. I think this is a good approach as it reduces variation not quality. I’d rather have both, but needs must as the devil drives.

Other tasks we may hire students for. There’s some great talent amongst our students and they work relatively cheaply, but gain experience and it looks good on the CV. They are going to be inexperienced but we exist to help make students better, so that’s not a big concern.

Other very time consuming things which Joe and Sarah did for us, such as producing videos, we’ll just have to do less of.

I plan to take a firm line with academics expecting the same bespoke service they’ve got used to. We already work both smart and hard. I’m not going to spend my weekends doing work unless it’s the bits I enjoy. What does make me sad is seeing an academic on the pay grade above me go and buy a book on PHP. His time costs the university more than mine.

Austerely Awesome

At the past two Institutional Web Managers Workshops we have all talked about how big cuts to university web teams were on the way. For my team they are now here. If it was just us I would be more unhappy than I am. There’s some comfort in knowing we did nothing wrong. We’ll not be able to do us much now, but we’ll still run the ECS web systems to the best of our ability. The best of our ability is pretty darn awesome. Our level of awesomeness will remain high, just the quantity will have to reduce a little.

So two coders go into a bar…

Anyhow, myself and my friend Patrick had a few pints and were discussing useful conversion tools that seem to be missing from the environment. It was pretty easy to knock up an RDF to JSON (or JSONP) interface. I code better after a drew frinks, honest.

Anyhow, here’s the tool:

• RDF2JSON

Your mileage may (will) vary as it’s pre-alpha-coded-in-a-bar-code. If this needs firming up into a service leave a comment or I’ll not worry about it too much. I know it does not yet handle unicodey stuff.