A theme of my last few years has been enabling the increased discoverability of Cultural Heritage resources by making the metadata about them more open and consumable.
Much of this work has been at the libraries end of the sector but I have always have had an eye on the broad Libraries, Archives, and Museums world, not forgetting Galleries of course.
Two years ago at the LODLAM Summit 2015 I ran a session to explore if it would be possible to duplicate in some way the efforts of the Schema Bib Extend W3C Community Group which proposed and introduced an extension and enhancements to the Schema.org vocabulary to improve its capability for describing bibliographic resources, but this time for archives physical, digital and web.
Interest was sufficient for me to setup and chair a new W3C Community Group, Schema Architypes. The main activity of the group has been the creation and discussion around a straw-man proposal for adding new types to the Schema.org vocabulary.
Not least the discussion has been focused on how the concepts from the world of archives (collections, fonds, etc.) can be represented by taking advantage of the many modelling patterns and terms that are already established in that generic vocabulary, and what few things would need to be added to expose archive metadata to aid discovery.
So why am I now suggesting that there maybe an opportunity for the discovery of archives and their resources?
In web terms for something to be discoverable it, or a description of it, needs to be visible on a web page somewhere. To take advantage of the current structured web data revolution, being driven by the search engines and their knowledge graphs they are building, those pages should contain structured metadata in the form of Schema.org markup.
Through initiatives such as ArchivesSpace and their application, and ArcLight it is clear that many in the world of archives have been focused on web based management, search, and delivery views of archives and the resources and references they hold and describe. As these are maturing it is clear that the need for visibility on the web is starting to be addressed.
So archives are now in a great place to grab the opportunity to take advantage of the benefits of Schema.org to aid discovery of their archives and what they contain. At least with these projects, they have the pages on which to embed that structured web data, once a consensus around the proposals from the Schema Architypes Group has formed.
I call out to those involved with the practical application of systems for the management, searching, and delivery of archives to at least take a look at the work of the group and possibly engage on a practical basis, exploring the potential and challenges for implementing Schema.org.
So if you want to understand more behind this opportunity, and how you might get involved, either join the W3C Group or contact me direct.
*Image acknowledgement to The Oberlin College Archives
Marketing Hype! I hear you thinking – well at least I didn’t use the tired old ‘Next Generation’ label.
Let me explain what is this fundamental component of what I am seeing potentially as a New Web, and what I mean by New Web.
This fundamental component I am talking about you might be surprised to learn is a vocabulary – Schema.org. But let me first set the context by explaining my thoughts on this New Web.
Having once been considered an expert on Web 2.0 (I hasten to add by others, not myself) I know how dangerous it can be to attach labels to things. It tends to spawn screen full’s of passionate opinions on the relevance of the name, date of the revolution, and over detailed analysis of isolated parts of what is a general movement. I know I am on dangerous ground here!
To my mind something is new when it feels different. The Internet felt different when the Web (aka HTTP + HTML + browsers) arrived. The Web felt different (Web 2.0?) when it became more immersive (write as well as read) and visually we stopped trying to emulate in a graphical style what we saw on character terminals. Oh, and yes we started to round our corners.
There have been many times over the last few years when it felt new – when it suddenly arrived in our pockets (the mobile web) – when the inner thoughts, and eating habits, of more friends that you ever remember meeting became of apparent headline importance (the social web) – when [the contents of] the web broke out of the boundaries of the browser and appeared embedded in every app, TV show, and voice activated device.
The feeling different phase I think we are going through at the moment, like previous times, is building on what went before. It is exemplified by information [data] breaking out of the boundaries of our web sites and appearing where it is useful for the user.
We are seeing the tip of this iceberg in the search engine Knowledge Panels, answer boxes, and rich snippets, The effect of this being that often your potential user can get what they need without having to find and visit your site – answering questions such as what is the customer service phone number for an organisation; is the local branch open at the moment;give me driving directions to it; what is available and on offer. Increasingly these interactions can occur without the user even being aware they are using the web – “Siri! Where is my nearest library?“ A great way to build relationships with your customers. However a new and interesting challenge for those trying to measure the impact of your web site.
So, what is fundamental to this New Web?
There are several things – HTTP, the light-weight protocol designed to transfer text, links and latterly data, across an internet previously used to specific protocols for specific purposes – HTML, that open, standard, easily copied light-weight extensible generic format for describing web pages that all browsers can understand – Microdata, RDFa, JSON, JSON-LD – open standards for easily embedding data into HTML – RDF, an open data format for describing things of any sort, in the form of triples, using shared vocabularies. Building upon those is Schema.org – an open, [de facto] standard, generic vocabulary for describing things in most areas of interest.
Why is one vocabulary fundamental when there are so many others to choose from? Check out the 500+ referenced on the Linked Open Vocabularies (LOV) site. Schema.org however differs from most of the others in a few key areas:
Size and scope – its current 642 Types and 992 Properties is significantly larger and covers far more domains of interest than most others. This means that if you are looking to describe a something, you are highly likely to to find enough to at least start. Despite its size, it is yet far from capable of describing everything on, or off, the planet.
Evolution – it is under continuous evolutionary development and extension, driven and guided by an open community under the wing of the W3C and accessible in a GitHub repository.
Flexibility – from the beginning Schema.org was designed to be used in a choice of your favourite serialisation – Microdata, RDFa, JSON-LD, with the flexibility of allowing values to default to text if you have not got a URI available.
Consumers – The major search engines Google, Bing, Yahoo!, and Yandex, not only back the open initiative behind Schema.org but actively search out Schema.org markup to add to their Knowledge Graphs when crawling your sites.
Guidance – If you search out guidance on supplying structured data to those major search engines, you are soon supplied with recommendations and examples for using Schema.org, such as this from Google. They even supply testing tools for you to validate your markup.
With this support and adoption, the Schema.org initiative has become self-fulfilling. If your objective is to share or market structured data about your site, organisation, resources, and or products with the wider world; it would be difficult to come up with a good reason not to use Schema.org.
Is it a fully ontologically correct semantic web vocabulary? Although you can see many semantic web and linked data principles within it, no it is not. That is not its objective. It is a pragmatic compromise between such things, and the general needs of webmasters with ambitions to have their resources become an authoritative part of the global knowledge graphs, that are emerging as key to the future of the development of search engines and the web they inhabit.
Note that I question if Schema.org is a fundamental component, of what I am feeling is a New Web. It is not the fundamental component, but one of many that over time will become just the way we do things.
The Culture Grid closed to ‘new accessions’ (ie. new collections of metadata) on the 30th April
The existing index and API will continue to operate in order to ensure legacy support
Museums, galleries, libraries and archives wishing to contribute material to Europeana can still do so via the ‘dark aggregator’, which the Collections Trust will continue to fund
Interested parties are invited to investigate using the Europeana Connection Kit to automate the batch-submission of records into Europeana
The reasons he gave for the ending of this aggregation service are enlightening for all engaged with or thinking about data aggregation in the library, museum, and archives sectors.
Throughout its history, the Culture Grid has been tough going. Looking back over the past 7 years, I think there are 3 primary and connected reasons for this:
The value proposition for aggregation doesn’t stack up in terms that appeal to museums, libraries and archives. The investment of time and effort required to participate in platforms like the Culture Grid isn’t matched by an equal return on that investment in terms of profile, audience, visits or political benefit. Why would you spend 4 days tidying up your collections information so that you can give it to someone else to put on their website? Where’s the kudos, increased visitor numbers or financial return?
Museum data (and to a lesser extent library and archive data) is non-standard, largely unstructured and dependent on complex relations. In the 7 years of running the Culture Grid, we have yet to find a single museum whose data conforms to its own published standard, with the result that every single data source has required a minimum of 3-5 days and frequently much longer to prepare for aggregation. This has been particularly salutary in that it comes after 17 years of the SPECTRUM standard providing, in theory at least, a rich common data standard for museums;
Metadata is incidental. After many years of pump-priming applications which seek to make use of museum metadata it is increasingly clear that metadata is the salt and pepper on the table, not the main meal. It serves a variety of use cases, but none of them is ‘proper’ as a cultural experience in its own right. The most ‘real’ value proposition for metadata is in powering additional services like related search & context-rich browsing.
The first of these two issues represent a fundamental challenge for anyone aiming to promote aggregation. Countering them requires a huge upfront investment in user support and promotion, quality control, training and standards development.
The 3rd is the killer though – countering these investment challenges would be possible if doing so were to lead directly to rich end-user experiences. But they don’t. Instead, you have to spend a huge amount of time, effort and money to deliver something which the vast majority of users essentially regard as background texture.
As an old friend of mine would depressingly say – Makes you feel like packing up your tent and going home!
Interestingly earlier in the post Nick give us an insight into the purpose of Culture Grid:
.… we created the Culture Grid with the aim of opening up digital collections for discovery and use ….
That basic purpose is still very valid for both physical and digital collections of all types. The what [helping people find, discover, view and use cultural resources] is as valid as it has ever been. It is the how [aggregating metadata and building shared discovery interfaces and landing pages for it] that has been too difficult to justify continuing in Culture Grid’s case.
In my recent presentations to library audiences I have been asking a simple question “Why do we catalogue?” Sometimes immediately, sometimes after some embarrassed shuffling of feet, I inevitably get the answer “So we can find stuff!“. In libraries, archives, and museums helping people finding the stuff we have is core to what we do – all the other things we do are a little pointless if people can’t find, or even be aware of, what we have.
If you are hoping your resources will be found they have to be referenced where people are looking. Where are they looking?
It is exceedingly likely they are not looking in your aggregated discovery interface, or your local library, archive or museum interface either. Take a look at this chart detailing the discovery starting point for college students and others. Starting in a search engine is up in the high eighty percents, with things like library web sites and other targeted sources only just making it over the 1% hurdle to get on the chart. We have known about this for some time – the chart comes from an OCLC Report ‘College Students’ Perceptions of Libraries and Information Resources‘ published in 2005. I would love to see a similar report from recent times, it would have to include elements such as Siri, Cortana, and other discovery tools built-in to our mobile devices which of course are powered by the search engines. Makes me wonder how few cultural heritage specific sources would actually make that 1% cut today.
Our potential users are in the search engines in one way or another, however it is the vast majority case that our [cultural heritage] resources are not there for them to discover.
Culture Grid, I would suggest, is probably not the only organisation, with an ‘aggregate for discovery’ reason for their existence, that may be struggling to stay relevant, or even in existence.
You may well ask about OCLC, with it’s iconic WorldCat.org discovery interface. It is a bit simplistic say that it’s 320 million plus bibliographic records are in WorldCat only for people to search and discover through the worldcat.org user interface. Those records also underpin many of the services, such as cooperative cataloguing, record supply, inter library loan, and general library back office tasks, etc. that OCLC members and partners benefit from. Also for many years WorldCat has been at the heart of syndication partnerships supplying data to prominent organisations, including Google, that help them reference resources within WorldCat.org which in turn, via find in a library capability, lead to clicks onwards to individual libraries. [Declaration: OCLC is the company name on my current salary check] Nevertheless, even though WorldCat has a broad spectrum of objectives, it is not totally immune from the influences that are troubling the likes of Culture Graph. In fact they are one of the web trends that have been driving the Linked Data and Schema.org efforts from the WorldCat team, but more of that later.
How do we get our resources visible in the search engines then? By telling the search engines what we [individual organisations] have. We do that by sharing a relevant view of our metadata about our resources, not necessarily all of it, in a form that the search engines can easily consume. Basically this means sharing data embeded in your web pages, marked up using the Schema.org vocabulary. To see how this works, we need look no further than the rest of the web – commerce, news, entertainment etc. There are already millions of organisations, measured by domains, that share structured data in their web pages using the Schema.org vocabulary with the search engines. This data is being used to direct users with more confidence directly to a site, and is contributing to the global web of data.
There used to be a time that people complained in the commercial world of always ending up being directed to shopping [aggregation] sites instead of directly to where they could buy the TV or washing machine they were looking for. Today you are far more likely to be given some options in the search engine that link you directly to the retailer. I believe is symptomatic of the disintermediation of the aggregators by individual syndication of metadata from those retailers.
Can these lessons be carried through to the cultural heritage sector – of course they can. This is where there might be a bit of light at the end of the tunnel for those behind the aggregations such as Culture Grid. Not for the continuation as an aggregation/discovery site, but as a facilitator for the individual contributors. This stuff, when you first get into it, is not simple and many organisations do not have the time and resources to understand how to share Schema.org data about their resources with the web. The technology itself is comparatively simple, in web terms, it is the transition and implementation that many may need help with.
Schema.org is not the perfect solution to describing resources, it is not designed to be. It is there to describe them sufficiently to be found on the web. Nevertheless it is also being evolved by community groups to enhance it capabilities. Through my work with the Schema Bib Extend W3C Community Group, enhancements to Schema.org to enable better description of bibliographic resources, have been successfully proposed and adopted. This work is continuing towards a bibliographic extension – bib.schema.org. There is obvious potential for other communities to help evolve and extend Schema to better represent their particular resources – archives for example. I would be happy to talk with others who want insights into how they may do this for their benefit.
Schema.org is not a replacement for our rich common data standards such as MARC for libraries, and SPECTRUM for museums as Nick describes. Those serve purposes beyond sharing information with the wider world, and should be continued to be used for those purposes whilst relevant. However we can not expect the rest of the world to get its head around our internal vocabularies and formats in order to point people at our resources. It needs to be a compromise. We can continue to use what is relevant in our own sectors whilst sharing Schema.org data so that our resources can be discovered and then explored further.
So to return to the question I posed – Is There Still a Case for Cultural Heritage Data Aggregation? – If the aggregation is purely for the purpose of supporting discovery, I think the answer is a simple no. If it has broader purpose, such as for WorldCat, it is not as clear cut.
I do believe nevertheless that many of the people behind the aggregations are in the ideal place to help facilitate the eventual goal of making cultural heritage resources easily discoverable. With some creative thinking, adoption of ‘web’ techniques, technologies and approaches to provide facilitation services, reviewing what their real goals are [which may not include running a search interface]. I believe we are moving into an era where shared authoritative sources of easily consumable data could make our resources more visible than we previously could have hoped.
Are there any black clouds on this hopeful horizon? Yes there is one. In the shape of traditional cultural heritage technology conservatism. The tendency to assume that our vocabulary or ontology is the only way to describe our resources, coupled with a reticence to be seen to engage with the commercial discovery world, could still hold back the potential.
As an individual library, archive, or museum scratching your head about how to get your resources visible in Google and not having the in-house ability to react; try talking within the communities around and behind the aggregation services you already know. They all should be learning and a problem shared is more easily solved. None of this is rocket science, but trying something new is often better as a group.
About a month ago Version 2.0 of the Schema.org vocabulary hit the streets.
This update includes loads of tweaks, additions and fixes that can be found in the release information. The automotive folks have got new vocabulary for describing Cars including useful properties such as numberofAirbags, fuelEfficiency, and knownVehicleDamages. New property mainEntityOfPage (and its inverse, mainEntity) provide the ability to tell the search engine crawlers which thing a web page is really about. With new type ScreeningEvent to support movie/video screenings, and a gtin12 property for Product, amongst others there is much useful stuff in there.
But does this warrant the version number clicking over from 1.xx to 2.0?
These new types and properties are only the tip of the 2.0 iceberg. There is a heck of a lot of other stuff going on in this release that apart from these additions. Some of it in the vocabulary itself, some of it in the potential, documentation, supporting software, and organisational processes around it.
Sticking with the vocabulary for the moment, there has been a bit of cleanup around property names. As the vocabulary has grown organically since its release in 2011, inconsistencies and conflicts between different proposals have been introduced. So part of the 2.0 effort has included some rationalisation. For instance the Code type is being superseded by SoftwareSourceCode – the term code has many different meanings many of which have nothing to do with software; surface has been superseded by artworkSurface and area is being superseded by serviceArea, for similar reasons. Check out the release information for full details. If you are using any of the superseded terms there is no need to panic as the original terms are still valid but with updated descriptions to indicate that they have been superseded. However you are encouraged to moved towards the updated terminology as convenient. The question of what is in which version brings me to an enhancement to the supporting documentation. Starting with Version 2.0 there will be published a snapshot view of the full vocabulary – here is http://schema.org/version/2.0. So if you want to refer to a term at a particular version you now can.
How often is Schema being used? – is a question often asked. A new feature has been introduced to give you some indication. Checkout the description of one of the newly introduced properties mainEntityOfPage and you will see the following: ‘Usage: Fewer than 10 domains‘. Unsurprisingly for a newly introduced property, there is virtually no usage of it yet. If you look at the description for the type this term is used with, CreativeWork, you will see ‘Usage: Between 250,000 and 500,000 domains‘. Not a direct answer to the question, but a good and useful indication of the popularity of particular term across the web.
This refers to the introduction of the functionality, on the Schema.org site, to host extensions to the core vocabulary. The motivation for this new approach to extending is explained thus:
Schema.org provides a core, basic vocabulary for describing the kind of entities the most common web applications need. There is often a need for more specialized and/or deeper vocabularies, that build upon the core. The extension mechanisms facilitate the creation of such additional vocabularies.
With most extensions, we expect that some small frequently used set of terms will be in core schema.org, with a long tail of more specialized terms in the extension.
As yet there are no extensions published. However, there are some on the way.
As Chair of the Schema Bib Extend W3C Community Group I have been closely involved with a proposal by the group for an initial bibliographic extension (bib.schema.org) to Schema.org. The proposal includes new Types for Chapter, Collection, Agent, Atlas, Newspaper & Thesis, CreativeWork properties to describe the relationship between translations, plus types & properties to describe comics. I am also following the proposal’s progress through the system – a bit of a learning exercise for everyone. Hopefully I can share the news in the none too distant future that bib will be one of the first released extensions.
W3C Community Group for Schema.org A subtle change in the way the vocabulary, it’s proposals, extensions and direction can be followed and contributed to has also taken place. The creation of the Schema.org Community Group has now provided an open forum for this.
So is 2.0 a bit of a milestone? Yes taking all things together I believe it is. I get the feeling that Schema.org is maturing into the kind of vocabulary supported by a professional community that will add confidence to those using it and recommending that others should.
Regular readers of this blog may well know I am an enthusiast for Schema.org – the generic vocabulary for describing things on the web as structured data, backed by the major search engines Google, Bing, Yahoo! & Yandex. When I first got my head around it back in 2011 I soon realised it’s potential for making bibliographic resources, especially those within libraries, a heck of a lot more discoverable. To be frank library resources did not, and still don’t, exactly leap in to view when searching the web – a bit of a problem when most people start searching for things with Google et al – and do not look elsewhere.
Schema.org as a generic vocabulary to describe most stuff, easily embedded in your web pages, has been a great success. As was reported by Google’s R.V. Guha, at the recent Semantic Technology and Business Conference in San Jose, a sample of 12B pages showed approximately 21% containing Schema.org markup. Right from the beginning, however, I had concerns about its applicability to the bibliographic world – great start with the Book type, but there were gaps the coverage for such things as journal issues & volumes, multi-volume works, citations, and the relationship between a work and its editions. Discovering others shared my combination of enthusiasm and concerns, I formed a W3C Community Group – Schema Bib Extend – to propose some bibliographic focused extensions to Schema.org. Which brings me to the events behind this post…
The SchemaBibEx group have had several proposals accepted over the last couple of years, such as making the [commercial] Offer more appropriate for describing loanable materials, and broadening of the citation property. Several other significant proposals were brought together in a package which I take great pleasure in reporting was included in the latest v1.9 release of Schema.org. For many in our group these latest proposals were a long time coming after their initial proposal. Although frustrating, the delays were symptomatic of a very healthy process.
Although the number of new types and properties are small, their addition to Schema opens up potential for much better description of periodicals and creative work relationships. To introduce the background to this, SchemaBibEx member Dan Scott and I were invited to jointly post on the Schema.org Blog.
So, another step forward for Schema.org. I believe that is more than just a step however, for those wishing to make the bibliographic resources more visible on the Web. There as been some criticism that Schema.org has been too simplistic to be able represent some of the relationships and subtleties from our world. Criticism that was not unfounded. Now with these enhancements, much of these criticisms are answered. There is more to do, but the major objective of the group that proposed them has been achieved – to lay the broad foundation for the description of bibliographic, and creative work, resources in sufficient detail for them to be understood by the search engines to become part of their knowledge graphs. Of course that is not the final end we are seeking. The reason we share data is so that folks are guided to our resources – by sharing, using the well understood vocabulary, Schema.org.
Examples of a conceptual creative work being related to its editions, using exampleOfWork and workExample, have been available for some time. In anticipation of their appearance in Schema, they were introduced into the OCLC WorldCat release of 194 million Work descriptions (for example: http://worldcat.org/entity/work/id/1363251773) with the inverse relationship being asserted in an updated version of the basic WorldCat linked data that has been available since 2012.
A couple of months back I spoke about the preview release of Works data from WorldCat.org. Today OCLC published a press release announcing the official release of 197 million descriptions of bibliographic Works.
A Work is a high-level description of a resource, containing information such as author, name, descriptions, subjects etc., common to all editions of the work. The description format is based upon some of the properties defined by the CreativeWork type from the Schema.org vocabulary. In the case of a WorldCat Work description, it also contains [Linked Data] links to individual, OCLC numbered, editions already shared from WorldCat.org.
These links (URIs) lead, where available, to authoritative sources for people, subjects, etc. When not available, placeholder URIs have been created to capture information not yet available or identified in such authoritative hubs. As you would expect from a linked data hub the works are available in common RDF serializations – Turtle, RDF/XML, N-Triples, JSON-LD – using the Schema.org vocabulary – under an open data license.
The obvious question is “how do I get a work id for the items in my catalogue?”. The simplest way is to use the already released linked data from WorldCat.org. If you have an OCLC Number (eg. 817185721) you can create the URI for that particular manifestation by prefixing it with ‘http://worldcat.org/oclc/’ thus: http://worldcat.org/oclc/817185721
In the linked data that is returned, either on screen in the Linked Data section, or in the RDF in your desired serialization, you will find the following triple which provides the URI of the work for this manifestation:
To quote Neil Wilson, Head of Metadata Services at the British Library:
With this release of WorldCat Works, OCLC is creating a significant, practical contribution to the wider community discussion on how to migrate from traditional institutional library catalogues to popular web resources and services using linked library data. This release provides the information community with a valuable opportunity to assess how the benefits of a works-based approach could impact a new generation of library services.
This is a major first step in a journey to provide linked data views of the entities within WorldCat. Looking forward to other WorldCat entities such as people, places, and events. Apart from major release of linked data, this capability is the result of applying [Big] Data mining and analysis techniques that have been the focus of research and development for several years. These efforts are demonstrating that there is much more to library linked data than the mechanical, record at a time, conversion of Marc records into an RDF representation.
You may find it helpful, in understanding the potential exposed by the release of Works, to review some of the questions and answers that were raised after the preview release.
Personally I am really looking forward to hearing about the uses that are made of this data.
One of the most challenging challenges in my evangelism of the benefits of using Schema.org for sharing data about resources via the web is that it is difficult to ‘show’ what is going on.
The scenario goes something like this…..
“Using the Schema.org vocabulary, you embed data about your resources in the HTML that makes up the page using either microdata or RDFa….”
At about this time you usually display a slide showing html code with embedded RDFa. It may look pretty but the chances of more than a few of the audience being able to pick out the schema:Book or sameAs or rdf:type elements out of the plethora of angle brackets and quotes swimming before their eyes is fairly remote.
Having asked them to take a leap of faith that the gobbledegook you have just presented them with, is not only simple to produce but also invisible to users viewing their pages – “but not to Google, which harvest that meaningful structured data from within your pages” – you ask them to take another leap [of faith].
You ask them to take on trust that Google is actually understanding, indexing and using that structured data. At this point you start searching for suitable screen shots of Google Knowledge Graph to sit behind you whilst you hypothesise about the latest incarnation of their all-powerful search algorithm, and how they imply that they use the Schema.org data to drive so-called Semantic Search.
I enjoy a challenge, but I also like to find a better way sometimes. w3
When OCLC first released Linked Data in WorldCat they very helpfully addressed the first of these issues by adding a visual display of the Linked Data to the bottom of each page. This made my job far easier!
But it has a couple of downsides. Firstly it is not the prettiest of displays and is only really of use to those interested in ‘seeing’ Linked Data. Secondly, I believe it creates an impression to some that, if you want Google to grab structured data about resources, you need to display a chunk of gobbledegook on your pages.
That simple way to easily show someone the data embedded in a page, is a great aid to understanding for those new to the concept. But that is not all. This excellent little extension has a couple of extra tricks up its sleeve.
It includes a visualisation of the [Linked Data] graph of relationships – the structure of the data. Clicking on any of the nodes of the display, causes the value of the subject, predicate, or object it represents to be displayed below the image and the relevant row(s) in the list of triples to be highlighted. As well as all this, there is a ‘Show Turtle’ button, which does just as you would expect opening up a window in which it has translated the triples into Turtle – Turtle being (after a bit of practise) the more human friendly way of viewing or creating RDF.
Green Turtle is a useful little tool which I would recommend to visualise microdata and RDFa, be it using the Schema.org vocabulary or not. I am already using it on WorldCat in preference to scrolling to the bottom of the page to click the Linked Data tab.
Custom Searches that know about Schema! Google have recently enhanced the functionality of their Custom Search Engine (CSE) to enable searching by Schema.org Types. Try out this example CSE which only returns results from WorldCat.org which have been described in their structured data as being of type schema:Book.
A simple yet powerful demonstration that not only are Google harvesting the Schema.org Linked Data from WorldCat, but they are also understanding it and are visibly using it to drive functionality.
I have just been sharing a platform, at the OCLC EMEA Regional Council Meeting in Cape Town South Africa, with my colleague Ted Fons. A great setting for a great couple of days of the OCLC EMEA membership and others sharing thoughts, practices, collaborative ideas and innovations.
Ted and I presented our continuing insight into The Power of Shared Data, and the evolving data strategy for the bibliographic data behind WorldCat. If you want to see a previous view of these themes you can check out some recordings we made late last year on YouTube, from Ted – The Power of Shared Data – and me – What the Web Wants.
Today, demonstrating on-going progress towards implementing the strategy, I had the pleasure to preview two upcoming significant announcements on the WorldCat data front:
The release of 194 Million Open Linked Data Bibliographic Work descriptions
The WorldCat Linked Data Explorer interface
A Work is a high-level description of a resource, containing information such as author, name, descriptions, subjects etc., common to all editions of the work. The description format is based upon some of the properties defined by the CreativeWork type from the Schema.org vocabulary. In the case of a WorldCat Work description, it also contains [Linked Data] links to individual, oclc numbered, editions already shared in WorldCat. Let’s take a look at one – try this: http://worldcat.org/entity/work/id/12477503
You will see, displayed in the new WorldCat Linked Data Explorer, a html view of the data describing ‘Zen and the art of motorcycle maintenance’. Click on the ‘Open All’ button to view everything. Anyone used to viewing bibliographic data will see that this is a very different view of things. It is mostly URIs, the only visible strings being the name or description elements. This is not designed as an end-user interface, it is designed as a data exploration tool. This is highlighted by the links at the top to alternative RDF serialisations of the data – Turtle, N-Triple, JSON-LD, RDF/XML.
Why is this a preview? Can I usefully use the data now? Are a couple of obvious questions for you to ask at this time.
This is the first production release of WorldCat infrastructure delivering linked data. The first step in what will be an evolutionary, and revolutionary journey, to provide interconnected linked data views of the rich entities (works, people, organisations, concepts, places, events) captured in the vast shared collection of bibliographic records that makes up WorldCat. Mining those, 311+ million, records is not a simple task, even to just identify works. It takes time, and a significant amount of [Big Data] computing resources. One of the key steps in this process is to identify where they exist connections between works and authoritative data hubs, such as VIAF, FAST, LCSH, etc. In this preview release, it is some of those connections that are not yet in place.
What you see in their place at the moment is a link to, what can be described as, a local authority. These are exemplified by what the data geeks call a hash-URI as its identifier. http://experiment.worldcat.org/entity/work/data/12477503#Person/pirsig_robert for example is such an identifier, constructed from the work URI and the person name. Over the next few weeks, where the information is available, you would expect to see this link replaced by a connection to VIAF, such as this: http://viaf.org/viaf/78757182.
So, can I use the data? – Yes, the data is live, and most importantly the work URIs are persistent. It is also available under an open data license (ODC-BY).
In a very few weeks, once the next update to the WorldCat linked data has been processed, you will find that links to works will be embedded in the already published linked data. For example you will find the following in the data for OCLC number 53474380:
What is next on the agenda? As described, within a few weeks, we expect to enhance the linking within the descriptions and provide links from the oclc numbered manifestations. From then on, both WorldCat and others will start to use WorldCat Work URIs, and their descriptions, as a core stable foundations to build out a web of relationships between entities in the library domain. It is that web of data that will stimulate the sharing of data and innovation in the design of applications and interfaces consuming the data over coming months and years.
As I said on the program today, we are looking for feedback on these releases.
We as a community are embarking on a new journey with shared, linked data at its heart. Its success will be based upon how that data is exposed, used, and the intrinsic quality of that data. Experience shows that a new view of data often exposes previously unseen issues, it is just that sort of feedback we are looking for. So any feedback on any aspect of this will be more than welcome.
I am excitedly looking forward to being able to comment further as this journey progresses.
The Art & Architecture Thesaurus is a reference of over 250,000 terms on art and architectural history, styles, and techniques. I’m sure this will become an indispensible authoritative hub of terms in the Web of Data to assist those describing their resources and placing them in context in that Web.
This is the fist step in an 18 month process to release four vocabularies – the others being The Getty Thesaurus of Geographic Names (TGN)®, The Union List of Artist Names®, and The Cultural Objects Name Authority (CONA)®.
A great step from Getty. I look forward to the others appearing over the months and seeing how rapidly their use is made across the web.
Little things mean a lot. Little things that are misunderstood often mean a lot more.
Take the OCLC Control Number, often known as the OCN, for instance.
Every time an OCLC bibliographic record is created in WorldCat it is given a unique number from a sequential set – a process that has already taken place over a billion times. The individual number can be found represented in the record it is associated with. Over time these numbers have become a useful part of the processing of not only OCLC and its member libraries but, as a unique identifier proliferated across the library domain, by partners, publishers and many others.
Like anything that has been around for many years, assumptions and even myths have grown around the purpose and status of this little string of digits. Many stem from a period when there was concern, being voiced by several including me at the time, about the potentially over restrictive reuse policy for records created by OCLC and its member libraries. It became assumed by some, that the way to tell if a bibliographic record was an OCLC record was to see if it contained an OCN. The effect was that some people and organisations invested effort in creating processes to remove OCNs from their records. Processes that I believe, in a few cases, are still in place.
I signalled that OCLC were looking at this, in my session (Linked Data Progress), at IFLA in Singapore a few weeks ago. I am now pleased to say that the wording I was hinting at has now appeared on the relevant pages of the OCLC web site:
Use of the OCLC Control Number (OCN) OCLC considers the OCLC Control Number (OCN) to be an important data element, separate from the rest of the data included in bibliographic records. The OCN identifies the record, but is not part of the record itself. It is used in a variety of human and machine-readable processes, both on its own and in subsequent manipulations of catalog data. OCLC makes no copyright claims in individual bibliographic elements nor does it make any intellectual property claims to the OCLC Control Number. Therefore, the OCN can be treated as if it is in the public domain and can be included in any data exposure mechanism or activity as public domain data. OCLC, in fact, encourages these uses as they provide the opportunity for libraries to make useful connections between different bibliographic systems and services, as well as to information in other domains.
The announcement of this confirmation/clarification of the status of OCNs was made yesterday by my colleague Jim Michalko on the Hanging Together blog.
When discussing this with a few people, one question often came up – Why just declare OCNs as public domain, why not license them as such? The following answer from the OCLC website, I believe explains why:
The OCN is an individual bibliographic element, and OCLC doesn’t make any copyright claims either way on specific data elements. The OCN can be used by other institutions in ways that, at an aggregate level, may have varying copyright assertions. Making a positive, specific claim that the OCN is in the public domain might interfere with the copyrights of others in those situations.
As I said, this is a little thing, but if it clears up some misunderstandings and consequential anomalies, it will contribute the usefulness of OCNs and ease the path towards a more open and shared data environment.