It is one thing to have a vision, regular readers of this blog will know I have them all the time, its yet another to see it starting to form through the mist into a reality. Several times in the recent past I have spoken of the some of the building blocks for bibliographic data to play a prominent part in the Web of Data. The Web of Data that is starting to take shape and drive benefits for everyone. Benefits that for many are hiding in plain site on the results pages of search engines. In those informational panels with links to people’s parents, universities, and movies, or maps showing the location of mountains, and retail outlets; incongruously named Knowledge Graphs.
OK, you may say, we’ve heard all that before, so what is new now?
As always it is a couple of seemingly unconnected events that throw things into focus.
Event 1: An article by David Weinberger in the DigitalShift section of Library Journal entitled Let The Future Go. An excellent article telling libraries that they should not be so parochially focused in their own domain whilst looking to how they are going serve their users’ needs in the future. Get our data out there, everywhere, so it can find its way to those users, wherever they are. Making it accessible to all. David references three main ways to provide this access:
APIs – to allow systems to directly access our library system data and functionality
Linked Data – can help us open up the future of libraries. By making clouds of linked data available, people can pull together data from across domains
The Library Graph – an ambitious project libraries could choose to undertake as a group that would jump-start the web presence of what libraries know: a library graph. A graph, such as Facebook’s Social Graph and Google’s Knowledge Graph, associates entities (“nodes”) with other entities
(I am fortunate to be a part of an organisation, OCLC, making significant progress on making all three of these a reality – the first one is already baked into the core of OCLC products and services)
It is the 3rd of those, however, that triggered recognition for me. Personally, I believe that we should not be focusing on a specific ‘Library Graph’ but more on the ‘Library Corner of a Giant Global Graph’ – if graphs can have corners that is. Libraries have rich specialised resources and have specific needs and processes that may need special attention to enable opening up of our data. However, when opened up in context of a graph, it should be part of the same graph that we all navigate in search of information whoever and wherever we are.
ZBW contributes to WorldCat, and has 1.2 million oclc numbers attached to it’s bibliographic records. So it seemed interesting, how many of these editions link to works and furthermore to other editions of the very same work.
The post is interesting from a couple of points of view. Firstly the simple steps they took to get at the data, really well demonstrated by the command-line calls used to access the data – get OCLCNum data from WorldCat.or in JSON format – extract the schema:exampleOfWork link to the Work – get the Work data from WorldCat, also in JSON – parse out the links to other editions of the work and compare with their own data. Command-line calls that were no doubt embedded in simple scripts.
Secondly, was the implicit way that the corpus of WorldCat Work entity descriptions, and their canonical identifying URIs, is used as an authoritative hub for Works and their editions. A concept that is not new in the library world, we have been doing this sort of things with names and person identities via other authoritative hubs, such as VIAF, for ages. What is new here is that it is a hub for Works and their relationships, and the bidirectional nature of those relationships – work to edition, edition to work – in the beginnings of a library graph linked to other hubs for subjects, people, etc.
The ZBW Labs experiment is interesting in its own way – simple approach enlightening results. What is more interesting for me, is it demonstrates a baby step towards the way the Library corner of that Global Web of Data will not only naturally form (as we expose and share data in this way – linked entity descriptions), but naturally fit in to future library workflows with all sorts of consequential benefits.
The experiment is exactly the type of initiative that we hoped to stimulate by releasing the Works data. Using it for things we never envisaged, delivering unexpected value to our community. I can’t wait to hear about other initiatives like this that we can all learn from.
So who is going to be doing this kind of thing – describing entities and sharing them to establish these hubs (nodes) that will form the graph. Some are already there, in the traditional authority file hubs: The Library of Congress LC Linked Data Service for authorities and vocabularies (id.loc.gov), VIAF, ISNI, FAST, Getty vocabularies, etc.
As previously mentioned Work is only the first of several entity descriptions that are being developed in OCLC for exposure and sharing. When others, such as Person, Place, etc., emerge we will have a foundation of part of a library graph – a graph that can and will be used, and added to, across the library domain and then on into the rest of the Global Web of Data. An important authoritative corner, of a corner, of the Giant Global Graph.
As I said at the start these are baby steps towards a vision that is forming out of the mist. I hope you and others can see it too.
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.
Help spotlight library innovation and send a library linked data practitioner to the SemTechBiz conference in San Francisco, June 2-5
Update from organisers: We are pleased to announce that Kevin Ford, from the Network Development and MARC Standards Office at the Library of Congress, was selected for the Semantic Web.com Spotlight on Innovation for his work with the Bibliographic Framework Initiative (BIBFRAME) and his continuing work on the Library of Congress’s Linked Data Service (loc.id). In addition to being an active contributor, Kevin is responsible for the BIBFRAME website; has devised tools to view MARC records and the resulting BIBFRAME resources side-by-side; authored the first transformation code for MARC data to BIBFRAME resources; and is project manager for The Library of Congress’ Linked Data Service. Kevin also writes and presents frequently to promote BIBFRAME, ID.LOC.GOV, and educate fellow librarians on the possibilities of linked data.
Without exception, each nominee represented great work and demonstrated the power of Linked Data in library systems, making it a difficult task for the committee, and sparking some interesting discussions about future such spotlight programs.
Congratulations, Kevin, and thanks to all the other great library linked data projects nominated!
OCLC and LITA are working to promote library participation at the upcoming Semantic Technology & Business Conference (SemTechBiz). Libraries are doing important work with Linked Data. SemanticWeb.com wants to spotlight innovation in libraries, and send one library presenter to the SemTechBiz conference expenses paid.
SemTechBiz brings together today’s industry thought leaders and practitioners to explore the challenges and opportunities jointly impacting both business leaders and technologists. Conference sessions include technical talks and case studies that highlight semantic technology applications in action. The program includes tutorials and over 130 sessions and demonstrations as well as a hackathon, start-up competition, exhibit floor, and networking opportunities. Amongst the great selection of speakers you will find yours truly!
If you know of someone who has done great work demonstrating the benefit of linked data for libraries, nominate them for this June 2-5 conference in San Francisco. This “library spotlight” opportunity will provide one sponsored presenter with a spot on the conference program, paid travel & lodging costs to get to the conference, plus a full conference pass.
Nominations for the Spotlight are being accepted through May 10th. Any significant practical work should have been accomplished prior to March 31st 2013 — project can be ongoing. Self-nominations will be accepted
Even if you do not nominate anyone, the Semantic Technology and Business Conference is well worth experiencing. As supporters of the SemanticWeb.com Library Spotlight OCLC and LITA members will get a 50% discount on a conference pass – use discount code “OCLC” or “LITA” when registering. (Non members can still get a 20% discount for this great conference by quoting code “FCLC”)
As is often the way, you start a post without realising that it is part of a series of posts – as with the first in this series. That one – Entification, the following one – Hubs of Authority and this, together map out a journey that I believe the library community is undertaking as it evolves from a record based system of cataloguing items towards embracing distributed open linked data principles to connect users with the resources they seek. Although grounded in much of the theory and practice I promote and engage with, in my role as Technology Evangelist with OCLC and Chairing the Schema Bib Extend W3C Community Group, the views and predictions are mine and should not be extrapolated to predict either future OCLC product/services or recommendations from the W3C Group.
Beacons of Availability
As I indicated in the first of this series, there are descriptions of a broader collection of entities, than just books, articles and other creative works, locked up in the Marc and other records that populate our current library systems. By mining those records it is possible to identify those entities, such as people, places, organisations, formats and locations, and model & describe them independently of their source records.
As I discussed in the post that followed, the library domain has often led in the creation and sharing of authoritative datasets for the description of many of these entity types. Bringing these two together, using URIs published by the Hubs of Authority, to identify individual relationships within bibliographic metadata published as RDF by individual library collections (for example the British National Bibliography, and WorldCat) is creating Library Linked Data openly available on the Web.
Why do we catalogue? is a question, I often ask, with an obvious answer – so that people can find our stuff. How does this entification, sharing of authorities, and creation of a web of library linked data help us in that goal. In simple terms, the more libraries can understand what resources each other hold, describe, and reference, the more able they are to guide people to those resources. Sounds like a great benefit and mission statement for libraries of the world but unfortunately not one that will nudge the needle on making library resources more discoverable for the vast majority of those that can benefit from them.
I have lost count of the number of presentations and reports I have seen telling us that upwards of 80% of visitors to library search interfaces start in Google. A similar weight of opinion can be found that complains how bad Google, and the other search engines, are at representing library resources. You will get some balancing opinion, supporting how good Google Book Search and Google Scholar are at directing students and others to our resources. Yet I am willing to bet that again we have another 80-20 equation or worse about how few, of the users that libraries want to reach, even know those specialist Google services exist. A bit of a sorry state of affairs when the major source of searching for our target audience, is also acknowledged to be one of the least capable at describing and linking to the resources we want them to find!
Library linked data helps solve both the problem of better description and findability of library resources in the major search engines. Plus it can help with the problem of identifying where a user can gain access to that resource to loan, download, view via a suitable license, or purchase, etc.
Before a search engine can lead a user to a suitable resource, it needs to identify that the resource exists, in any form, and hold a description for display in search results that will be sufficiently inform a user as such. Library search interfaces are inherently poor sources of such information, with web crawlers having to infer, from often difficult to differentiate text, what the page might be about. This is not a problem isolated to library interfaces. In response, the major search engines have cooperated to introduce a generic vocabulary for embedded structured information in to web pages so that they can be informed in detail what the page references. This vocabulary is Schema.org – I have previously posted about its success and significance.
With a few enhancements in the way it can describe bibliographic resources (currently being discussed by the Schema Bib Extend W3C Community Group) Schema.org is an ideal way for libraries to publish information about our resources and associated entities in a format the search engines can consume and understand. By using URIs for authorities in that data to identify, the author in question for instance using his/her VIAF identifier, gives them the ability to identify resources from many libraries associated by the same person. With this greatly enriched, more structured, linked to authoritative hubs, view of library resources, the likes of Google over time will stand a far better chance of presenting potential library users with useful informative results. I am pleased to say that OCLC have been at the forefront of demonstrating this approach by publishing Schema.org modelled linked data in the default WorldCat.org interface.
For this approach to be most effective, many of the major libraries, consortia, etc. will need to publish metadata as linked data, in a form that the search engines can consume whilst (following linked data principles) linking to each other when they identify that they are describing the same resource. Many instances of [in data terms] the same thing being published on the web will naturally raise its visibility in results listings.
An individual site (even a WorldCat) has difficultly in being identified above the noise of retail and other sites. We are aware of the Page Rank algorithms used by the search engines to identify and boost the reputation of individual sites and pages by the numbers of links between them. If not an identical process, it is clear that similar rules will apply for structured data linking. If twenty sites publish their own linked data about the same thing, the search engines will take note of each of them. If each of those sites assert that their resource is the same resource as a few of their partner sites (building a web of connection between instances of the same thing), I expect that the engines will take exponentially more notice.
Page ranking does not depend on all pages having to link to all others. Like many things on the web, hubs of authority and aggregation will naturally emerge with major libraries, local, national, and global consortia doing most of the inter-linking, providing interdependent hubs of reputation for others to connect with.
Having identified a resource that may satisfy a potential library user’s need, the next even more difficult problem is to direct that user to somewhere that they can gain access to it – loan, download, view via an appropriate licence, or purchase, etc.
WorldCat.org, and other hubs, with linked data enhanced to provide holdings information, may well provide a target to link via which a user may access to, in addition to just getting a description of, a resource. However, those few sites, no matter how big or well recognised they are, are just a few sites shouting in the wilderness of the ever increasing web. Any librarian in any individual library can quite rightly ask how to help Google, and the others, to point users at the most appropriate copy in his/her library.
We have all experienced the scenario of searching for a car rental company, to receive a link to one within walking distance as first result – or finding the on-campus branch at the top of a list of results.in response to a search for banks. We know the search engines are good at location, either geographical or interest, based searching so why can they not do it for library resources. To achieve this a library needs to become an integral part of a Web of Library Data, publishing structured linked data about the resources they have available for the search engines to find; in that data linking their resources to the reputable hubs of bibliographic that will emerge, so the engines know it is another reference to the same thing; go beyond basic bibliographic description to encompass structured data used by the commercial world to identify availability.
So who is going to do all this then – will every library need to employ a linked data expert? I certainly hope not.
One would expect the leaders in this field, national libraries, OCLC, consortia etc to continue to lead the way, in the process establishing the core of this library web of data – the hubs. Building on that framework the rest of the web can be established with the help of the products, and services of service providers and system suppliers. Those concerned about these things should already be starting to think about how they can be helped not only to publish linked data in a form that the search engines can consume, but also how their resources can become linked via those hubs to the wider web.
By lighting a linked data beacon on top of their web presence, a library will announce to the world the availability of their resources. One beacon is not enough. A web of beacons (the web of library data) will alert the search engines to the mass of those resources in all libraries, then they can lead users via that web to the appropriately located individual resource in particular.
This won’t happen over night, but we are certainly in for some interesting times ahead.
As is often the way, you start a post without realising that it is part of a series of posts – as with the first in this series. That one – Entification, and the next in the series – Beacons of Availability, together map out a journey that I believe the library community is undertaking as it evolves from a record based system of cataloguing items towards embracing distributed open linked data principles to connect users with the resources they seek. Although grounded in much of the theory and practice I promote and engage with, in my role as Technology Evangelist with OCLC and Chairing the Schema Bib Extend W3C Community Group, the views and predictions are mine and should not be extrapolated to predict either future OCLC product/services or recommendations from the W3C Group.
Hubs of Authority
Libraries, probably because of their natural inclination towards cooperation, were ahead of the game in data sharing for many years. The moment computing technology became practical, in the late sixties, cooperative cataloguing initiatives started all over the world either in national libraries or cooperative organisations. Two from personal experience come to mind, BLCMP started in Birmingham, UK in 1969 eventually evolved in to the leading Semantic Web organisation Talis, and in 1967 Dublin, Ohio saw the creation of OCLC. Both in their own way having had significant impact on the worlds of libraries, metadata, and the web (and me!).
One of the obvious impacts of inter-library cooperation over the years has been the authorities, those sources of authoritative names for key elements of bibliographic records. A large number of national libraries have such lists of agreed formats for author and organisational names. The Library of Congress has in addition to its name authorities, subjects, classifications, languages, countries etc. Another obvious success in this area is VIAF, the Virtual International Authority File, which currently aggregates over thirty authority files from all over the world – well used and recognised in library land, and increasingly across the web in general as a source of identifiers for people & organisations..
These authority files play a major role in the efficient cataloguing of material today, either by being part of the workflow in a cataloguing interface, or often just using the wonders of Windows ^C & ^V keystroke sequences to transfer agreed format text strings from authority sites into Marc record fields.
It is telling that the default [librarian] description of these things is a file – an echo back to the days when they were just that, a file containing a list of names. Almost despite their initial purpose, authorities are gaining a wider purpose. As a source of names for, and growing descriptions of, the entities that the library world is aware of. Many authority file hosting organisations have followed the natural path, in this emerging world of Linked Data, to provide persistent URIs for each concept plus publishing their information as RDF.
These, Linked Data enabled, sources of information are developing importance in their own right, as a natural place to link to, when asserting the thing, person, or concept you are identifying in your data. As Sir Tim Berners-Lee’s fourth principle of Linked Data tells us to “Include links to other URIs. so that they can discover more things”. VIAF in particular is becoming such a trusted, authoritative, source of URIs that there is now a VIAFbot responsible for interconnecting Wikipedia and VIAF to surface hundreds of thousands of relevant links to each other. A great hat-tip to Max Klein, OCLC Wikipedian in Residence, for his work in this area.
Libraries and librarians have a great brand image, something that attaches itself to the data and services they publish on the web. Respected and trusted are a couple of words that naturally associate with bibliographic authority data emanating from the library community. This data, starting to add value to the wider web, comes from those Marc records I spoke about last time. Yet it does not, as yet, lead those navigating the web of data to those resources so carefully catalogued. In this case, instead of cataloguing so people can find stuff, we could be considered to be enriching the web with hubs of authority derived from, but not connected to, the resources that brought them into being.
So where next? One obvious move, that is already starting to take place, is to use the identifiers (URIs) for these authoritative names to assert within our data, facts such as who a work is by and what it is about. Check out data from the British National Bibliography or the linked data hidden in the tab at the bottom of a WorldCat display – you will see VIAF, LCSH and other URIs asserting connection with known resources. In this way, processes no longer need to infer from the characters on a page that they are connected with a person or a subject. It is a fundamental part of the data.
With that large amount of rich [linked] data, and the association of the library brand, it is hardly surprising that these datasets are moving beyond mere nodes on the web of data. They are evolving in to Hubs of Authority, building a framework on which libraries and the rest of the web, can hang descriptions of, and signposts to, our resources. A framework that has uses and benefits beyond the boundaries of bibliographic data. By not keeping those hubs ‘library only’, we enable the wider web to build pathways to the library curated resources people need to support their research, learning, discovery and entertainment.
As is often the way, you start a post without realising that it is part of a series of posts – as with this one. This, and the following two posts in the series – Hubs of Authority, and Beacons of Availability – together map out a journey that I believe the library community is undertaking as it evolves from a record based system of cataloguing items towards embracing distributed open linked data principles to connect users with the resources they seek. Although grounded in much of the theory and practice I promote and engage with, in my role as Technology Evangelist with OCLC and Chairing the Schema Bib Extend W3C Community Group, the views and predictions are mine and should not be extrapolated to predict either future OCLC product/services or recommendations from the W3C Group.
Entification – a bit of an ugly word, but in my day to day existence one I am hearing more and more. What an exciting life I lead…
What is it, and why should I care, you may be asking.
I spend much of my time convincing people of the benefits of Linked Data to the library domain, both as a way to publish and share our rich resources with the wider world, and also as a potential stimulator of significant efficiencies in the creation and management of information about those resources. Taking those benefits as being accepted, for the purposes of this post, brings me into discussion with those concerned with the process of getting library data into a linked data form.
That phrase ‘getting library data into a linked data form’ hides multitude of issues. There are some obvious steps such as holding and/or outputting the data in RDF, providing resources with permanent URIs, etc. However, deriving useful library linked data from a source, such as a Marc record, requires far more than giving it a URI and encoding what you know, unchanged, as RDF triples.
Marc is a record based format. For each book catalogued, a record created. The mantra driven in to future cataloguers at library school has been, and I believe often still is, catalogue the item in your hand. Everything discoverable about that item in their hand is transferred on to that [now virtual] catalogue card stored in their library system. In that record we get obvious bookish information such as title, size, format, number of pages, isbn, etc. We also get information about the author (name, birth/death dates etc.), publisher (location, name etc.), classification scheme identifiers, subjects, genres, notes, holding information, etc., etc., etc. A vast amount of information about, and related to, that book in a single record. A significant achievement – assembling all this information for the vast majority of books in the vast majority of the libraries of the world. In this world of electronic resources a pattern that is being repeated for articles, journals, eBooks, audiobooks, etc.
Why do we catalogue? A question I often ask with an obvious answer – so that people can find our stuff. Replicating the polished draws of catalogue cards of old, ordered by author name or subject, indexes are applied to the strings stored in those records . Indexes acting as search access points to a library’s collection.
A spin-off of capturing information in record attributes, about library books/articles/etc., is that we are also building up information about authors, publishers subjects and classifications. So for instance a subject index will contain a list of all the names of the subjects addressed by an individual library collection. To apply some consistency between libraries, authorities – authoritative sets of names, subject headings etc., have emerged so that spellings and name formats could be shared in a controlled way between libraries and cataloguers.
So where does entification come in? Well, much of the information about authors subjects, publishers, and the like is locked up in those records. A record could be taken as describing an entity, the book. However the other entities in the library universe are described as only attributes of the book/article/text. I can attest to the vast computing power and intellectual effort that goes into efforts at OCLC to mine these attributes from records to derive descriptions of the entities they represent – the people, places, organisations, subjects, etc. that the resources are by, about, or related to in some way.
Once the entities are identified, and a model is produced & populated from the records, we can start to work with a true multi-dimensional view of our domain. A major step forward from the somewhat singular view that we have been working with over previous decades. With such a model it should be possible to identify and work with new relationships, such as publishers and their authors, subjects and collections, works and their available formats.
We are in a state of change in the library world which entification of our data will help us get to grips with. As you can imagine as these new approaches crystallise, they are leading to all sorts of discussions around what are the major entities we need to concern ourselves with; how do we model them; how do we populate that model from source [record] data; how do we do it without compromising the rich resources we are working with; and how do we continue to provide and improve the services relied upon at the moment, whilst change happens. Challenging times – bring on the entification!
Back in September I formed a W3C Group – Schema Bib Extend. To quote an old friend of mine “Why did you go and do that then?”
Well, as I have mentioned before Schema.org has become a bit of a success story for structured data on the web. I would have no hesitation in recommending it as a starting point for anyone, in any sector, wanting to share structured data on the web. This is what OCLC did in the initial exercise to publish the 270+ million resources in WorldCat.org as Linked Data.
The need to extend the Schema.org vocabulary became clear when using it to mark up the bibliographic resources in WorldCat. The Book type defined in Schema.org, along with other types derived from CreativeWork, contain many of the properties you need to describe bibliographic resources, but is lacking in some of the more detailed ones, such as holdings count and carrier type, we wanted to represent. It was also clear that it would need more extension if we wanted to go further to define the relationships between such things as works, expressions, manifestations, and items – to talk FRBR for a moment.
The organisations behind Schema.org (Google, Bing, Yahoo, Yandex) invite proposals for extension of the vocabulary via the W3C public-vocabs mailing list. OCLC could have taken that route directly, but at best I suggest it would have only partially served the needs of the broad spread of organisations and people who could benefit from enriched description of bibliographic resources on the web.
So that is why I formed a W3C Community Group to build a consensus on extending the Schema.org vocabulary for these types of resources. I wanted to not only represent the needs, opinions, and experience of OCLC, but also the wider library sector of libraries, librarians, system suppliers and others. Any generally applicable vocabulary [most importantly recognised by the major search engines] would also provide benefit for the wider bibliographic publishing, retailing, and other interested sectors.
Four months, and four conference calls (supported by OCLC – thank you), later we are a group of 55 members with a fairly active mailing list. We are making progress towards shaping up some recommendations having invested much time in discussing our objectives and the issues of describing detailed bibliographic information (often to be currently found in Marc, Onix, or other industry specific standards) in a generic web-wide vocabulary. We are not trying to build a replacement for Marc, or turn Schema.org into a standard that you could operate a library community with.
Applying Schema.org markup to your bibliographic data is aimed at announcing it’s presence, and the resources it describes, to the web and linking them into the web of data. I would expect to see it being applied as complementary markup to other RDF based standards such as BIBFRAME as it emerges. Although Schema.org started with Microdata and, latterly [and increasingly] RDFa, the vocabulary is equally applicable serialised in any of the RDF formats (N-Triples, Tertle, RDF/XML, JSON) for processing and data exchange purposes.
My hope over the next few months is that we will agree and propose some extensions to schema.org (that will get accepted) especially in the areas of work/manifestation relationships, representations of identifiers other than isbn, defining content/carrier, journal articles, and a few others that may arise. Something that has become clear in our conversations is that we also have a role as a group in providing examples of how [extended] Schema.org markup should be applied to bibliographic data.
I would characterise the stage we are at, as moving from the talking about it to doing something about it stage. I am looking forward to the next few months with enthusiasm.
If you want to join in, you will find us over at http://www.w3.org/community/schemabibex/ (where you will amongst other things on the Wiki find recordings and chat transcripts from the meetings so far). If you or your group want to know more about Schema.org and it’s relevance to libraries and the broader bibliographic world, drop me a line or, if I can fit it in with my travels to conferences such as ALA, could be persuaded to stand up and talk about it.
You may remember my frustration a couple of months ago, at being in the air when OCLC announced the addition of Schema.org marked up Linked Data to all resources in WorldCat.org. Those of you who attended the OCLC Linked Data Round Table at IFLA 2012 in Helsinki yesterday, will know that I got my own back on the folks who publish the press releases at OCLC, by announcing the next WorldCat step along the Linked Data road whilst they were still in bed.
The Round Table was an excellent very interactive session with Neil Wilson from the British Library, Emmanuelle Bermes from Centre Pompidou, and Martin Malmsten of the Nation Library of Sweden, which I will cover elsewhere. For now, you will find my presentation Library Linked Data Progress on my SlideShare site.
After we experimentally added RDFa embedded linked data, using Schema.org markup and some proposed Library extensions, to WorldCat pages, one the most often questions I was asked was where can I get my hands on some of this raw data?
We are taking the application of linked data to WorldCat one step at a time so that we can learn from how people use and comment on it. So at that time if you wanted to see the raw data the only way was to use a tool [such as the W3C RDFA 1.1 Distiller] to parse the data out of the pages, just as the search engines do.
So I am really pleased to announce that you can now download a significant chunk of that data as RDF triples. Especially in experimental form, providing the whole lot as a download would have bit of a challenge, even just in disk space and bandwidth terms. So which chunk to choose was a question. We could have chosen a random selection, but decided instead to pick the most popular, in terms of holdings, resources in WorldCat – an interesting selection in it’s own right.
To make the cut, a resource had to be held by more than 250 libraries. It turns out that almost 1.2 million fall in to this category, so a sizeable chunk indeed. To get your hands on this data, download the 1Gb gzipped file. It is in RDF n-triples form, so you can take a look at the raw data in the file itself. Better still, download and install a triplestore [such as 4Store], load up the approximately 80 million triples and practice some SPARQL on them.
Another area of question around the publication of WorldCat linked data, has been about licensing. Both the RDFa embedded, and the download, data are published as open data under the Open Data Commons Attribution License (ODC-BY), with reference to the community norms put forward by the members of the OCLC cooperative who built WorldCat. The theme of many of the questions have been along the lines of “I understand what the license says, but what does this mean for attribution in practice?”
To help clarify how you might attribute ODC-BY licensed WorldCat, and other OCLC linked data, we have produced attribution guidelines to help clarify some of the uncertainties in this area. You can find these at http://www.oclc.org/data/attribution.html. They address several scenarios, from documents containing WorldCat derived information to referencing WorldCat URIs in your linked data triples, suggesting possible ways to attribute the OCLC WorldCat source of the data. As guidelines, they obviously can not cover every possible situation which may require attribution, but hopefully they will cover most and be adapted to other similar ones.
As I say in the press release, posted after my announcement, we are really interested to see what people will do with this data. So let us know, and if you have any comments on any aspect of its markup, schema.org extensions, publishing, or on our attribution guidelines, drop us a line at email@example.com.
Even more recently I note that OCLC, at their EMEA Regional Council Meeting in Birmingham this week, see Linked Data as an important topic on the library agenda.
The consequence of this rise interest in library Linked Data is that the community is now exploring and debating how to migrate library records from formats such as Marc into this new RDF. In my opinion there is a great danger here of getting bogged down in the detail of how to represent every scintilla of information from a library record in every linked data view that might represent the thing that record describes. This is hardly unsurprising as most engaged in the debate come from an experience where if something was not preserved on a physical or virtual record card, it would be lost forever. By concentrating on record/format transformation I believe that they are using a Linked Data telescope to view their problem, but are not necessarily looking through the correct end of that telescope.
Let me explain what I mean by this. There is a massive duplication of information in library catalogues. For example, every library record describing a copy of a book about a certain boy wizard will contain one or more variations of the string of characters “Rowling, K. J”. To us humans it is fairly easy for us to infer that all of them represent the same person, as described by each cataloguer. For a computer, they are just strings of characters.
OCLC host the Virtual International Authority File (VIAF) project which draws together these strings of characters and produces a global identifier for each author. Associated with that author they collect the local language representations of their name.
One simple step down the Linked Data road would be to replace those strings of characters in those records with the relevant VIAF permalink, or URI – http://viaf.org/viaf/116796842/. One result of this would be that your system could follow that link and return an authoritative naming of that person, with the added benefit of it being available in several languages. A secondary, and more powerful, result is that any process scanning such records can identify exactly which [VIAF identified] person is the creator, regardless of the local language or formatting practices.
Why stop at the point of only identifying creators with globally unique identifiers. Why not use an identifier to represent the combined concept of a text, authored by a person, published by an organisation, in the form of a book – each of those elements having their own unique identifiers. If you enabled such a system on the Linked Data web, what would a local library catalogue need to contain? – Probably only a local identifier of some sort with links to local information such as supplier, price, date of purchase, license conditions, physical location, etc. plus a link to the global description provided by a respected source such as Open Library, Library of Congress, British Library, OCLC etc. A very different view of what might constitute a record in a local library.
So far I have looked at this from the library point of view. What about the view from the rest of the world?
I contend that most wishing to reference books, journal articles, curated and provided by libraries would happiest if they could refer to a global identifier that represents the concept of a particular work. Such consumers would only need a small sub-set of the data assembled by a library for basic display and indexing purposes – title, author. The next question may be, where is there a locally available copy of this book or article that I can access. In the model I describe, where these global identifiers are linked to local information such as loan status, the lookup would be a simple process compared with a current contrived search against inferred strings of characters.
Currently Google and other search engines have great difficulty in managing the massive amount of library catalogue pages that will mach a search for a book title. As referred to previously, Google are assembling a graph of related things. In this context the thing is the concept of the book or article, not the thousands of library catalogue pages describing the same thing.
Pulling these thoughts together, and looking down the Linked Data telescope from the non-library end, I envisage a layered approach to accessing library data.
A simple global identifier, or interlinked identifiers from several respected sources, that represents the concept of a particular thing (book, article, etc.)
A simple set of high-level description information for each thing – links to author, title, etc., associated with the identifier. This level of information would be sufficient for many uses on the web and could contain only publicly available information.
For those wishing more in depth bibliographic information, those unique identifiers, either directly or via SameAs links, could link you to more of the rich resources catalogued by libraries around the world, which may or may not be behind slightly less open licensing or commercial constraints.
Finally library holding/access information would be available, separate from the constraints of the bibliographic information, but indexed by those global identifiers.
To get us to such a state will require a couple of changes in the way libraries do things.
Firstly the rich data collated in current library records should be used to populate a Lined Data data model of the things those records describe – not just reproducing the records we have in another format. An approach I expanded upon in a previous post Create Data Not Records.
Secondly, as such a change would be a massive undertaking, libraries will need to work together to do this. The centralised library data holders have a great opportunity to drive this forward. A few years ago, the distributed hosted-on-site landscape of library management systems would have prevented such a change happening. However with library system software-as-a-service becoming an increasingly viable option for many, it is not the libraries that would have to change, just the suppliers of the systems the use.
My message here is that we need to be creating data, not records, and that we need to create the data first, then build records with it for those applications where records are needed.
Karen was addressing the result of looking at the move, of bibliographic metadata in to Linked Data and by definition RDF, from the “I’ve got all these records that I think I want to preserve” end of the telescope. She points out there are many translation efforts focused upon representing library record formats such as ISBD, FRBR, RDA, MODS and Marc in RDF, none of which have been endorsed by a standards body and all mutuality incompatible information silos. With an enlightening explanation of how there are more ways, to describe the Place of Publication in library land, than you can shake a stick at, she identifies that these are conditioned by context. A context that travels with the translations from a library record format in to an RDF representation thereof.
This is the antithesis of the linked data concept, where data sets from diverse sources share metadata elements. It is this re-use of elements that creates the “link” in linked data. To achieve this, metadata elements need to be unconstrained by a particular context.
It is interesting to note that this first use of the words Linked Data in the post, and a significant way in to her text. I believe this is symptomatic of the audience Karen is trying to enlighten and convince. For decades they have been focused on tightly controlled record formats and rules. So much so that the business model for a new format appears to be based upon marketing the documentation required to understand and apply it. It is hardly surprising therefore, that they hook on to RDF as a ‘standard’ and then try to represent and enforce their context upon it. Yes they end up with valid RDF (that is not difficult as you can represent almost anything in RDF), but is it useful Linked Data – more often than not – no.
I find it helps, to visualise how information should be captured as Linked Data, by approaching it from the point of view of a non-domain expert. With that hat on, the place of publication is easy – eg. London = the place where the publisher that published the item was located. A library domain expert would explain how under certain circumstances, such as a printing error or a special context, it is not that simple. The non-domain expert would also assert in my example that the London in place of publication, is the same London as the subject of the book, the same London referenced in the text, the same London that the author resided in, the same London in the title, the same London in which you can find a library to loan a copy from, and the same London that has http://dbpedia.org/resource/London as it’s DbPedia URI. I leave you to imagine the response from your favourite librarian…
So how do we square this circle – by, as Karen says, creating data, not records. We can create some data describing London as a place with it’s geographic location, and strings of characters in different languages that are accepted as it’s name. We could then create some more about a book, even more about a publication event (date, a link to a publisher, and a link to the place we just described). If later on we, or someone else, want to point to [link] our London piece of data as describing the place the book is about that would be equally valid, and not detrimental to the relationships we had created between it and any other data entities we described earlier.
Although we can not un-invent them, I see these translations to RDF as unhelpful. What is needed are entity extraction and linking processes to help create the entity descriptions we need from the information captured in the individual record silos that we have built up over the decades.
In her comments, Karen points to the data model(pdf) used by the British Library when publishing the British National Bibliography as Linked Data. A project, with which I was associated, that took the approach I describe, and is well worth a look at. When you do, remember that it is a first pass at modelling their data which will be built upon later by the BL and others. If you do not see your favourite, FRBR or other, relationships represented, why not comment on how they could be added to the model alongside the relationships already represented. That is one of the major benefits of using RDF and Linked Data, you can mix different ways of expressing relationships in a single model.