2011 has in a sense been the year of library linked data. Not that libraries of all kinds are now publishing and consuming linked data in great numbers. No. But we have witnessed the publication of the final report of the W3C Library Linked Data Incubator Group, the Library of Congress announcement of the new Bibliographic Framework for the Digital Age based on Linked Data and RDF, the release by a number of large libraries and library consortia of their bibliographic metadata, many publications, sessions and presentations on the subject.
All these events focus mainly on publishing library bibliographic metadata as linked open data. Personally I am not convinced that this is the most interesting type of data that libraries can provide. Bibliographic metadata as such describe publications, in the broadest sense, providing information about title, authors, subjects, editions, dates, urls, but also physical attributes like dimensions, number of pages, formats, etc. This type of information, in FRBR terms: Work, Expression and Manifestation metadata, is typically shared among a large number of libraries, publishers, booksellers, etc. ‘Shared’ in this case means ‘multiplied and redundantly stored in many different local systems‘. It doesn’t really make sense if all libraries in the world publish identical metadata side by side, does it?
In essence only really unique data is worth publishing. You link to the rest.
Currently, library data that is really unique and interesting is administrative information about holdings and circulation. After having found metadata about a potentially relevant publication it is very useful for someone to know how and where to get access to it, if it’s not freely available online. Do you need to go to a specific library location to get the physical item, or to have access to the online article? Do you have to be affiliated to a specific institution to be entitled to borrow or access it?
Usage data about publications, both print and digital, can be very useful in establishing relevance and impact. This way information seekers can be supported in finding the best possible publications for their specific circumstances. There are some interesting projects dealing with circulation data already, such as the research project by Magnus Pfeffer and Kai Eckert as presented at the SWIB 11 conference, and the JISC funded Library Impact Data project at the University of Huddersfield. The Ex Libris bX service presents article recommendations based on SFX usage log analysis.
The consequence of this assertion is that if libraries want to publish linked open data, they should focus on holdings and circulation data, and for the rest link to available bibliographic metadata as much as possible. It is to be expected that the Library of Congress’ New Bibliographic Framework will take care of that part one way or another.
In order to achieve this libraries should join forces with each other and with publishers and aggregators to put their efforts into establishing shared global bibliographic metadata pools accessible through linked open data. We can think of already existing data sources like WorldCat, OpenLibrary, Summon, Primo Central and the like. We can only hope that commercial bibliographic metadata aggregators like OCLC, SerialsSolutions and Ex Libris will come to realise that it’s in everybody’s interest to contribute to the realisation of the new Bibliographic Framework. The recent disagreement between OCLC and the Swedish National Library seems to indicate that this may take some time. For a detailed analysis of this see the blog post ‘Can linked library data disrupt OCLC? Part one’.
An interesting initiative in this respect is LibraryCloud, an open, multi-library data service that aggregates and delivers library metadata. And there is the HBZ LOBID project, which is targeted at ‘the conversion of existing bibliographic data and associated data to Linked Open Data‘.
So what would the new bibliographic framework look like? If we take the FRBR model as a starting point, the new framework could look something like this. See also my slideshow “Linked Open Data for libraries”, slides 39-42.
The basic metadata about a publication or a unit of content, on the FRBR Work level, would be an entry in a global datastore identified by a URI ( Uniform Resource Identifier). This datastore could for instance be WorldCat, or OpenLibrary, or even a publisher’s datastore. It doesn’t really matter. We don’t even have to assume it’s only one central datastore that contains all Work entries.
The thing identified by the URI would have a text string field associated with it containing the original title, let’s say “The Da Vinci Code” as an example of a book. But also articles can and should be identified this way. The basic information we need to know about the Work would be attached to it using URIs to other things in the linked data web. A set of two things linked by a URI is called a ‘triple’. ‘Author’ could for instance be a link to OCLC’s VIAF (http://viaf.org/viaf/102403515 = Dan Brown), which would then constitute a triple. If there are more authors, you simply add a URI for every person or institution. Subjects could be links to DBPedia/Wikipedia, Freebase, the Library of Congress Authority files, etc. There could be some more basic information, maybe a year, or a URI to a source describing the background of the work.
At the Expression level, a Dutch translation would have it’s own URI, stored in the same or another datastore. I could imagine that the publisher who commissioned the translation would maintain a datastore with this information. Attached to the Expression there would be the URI of the original Work, a URI pointing to the language, a URI identifying the translator and a text string contaning the Dutch title, among others.
Every individual edition of the work could have it’s own Manifestation level URI, with a link to the Expression (in this case the Dutch translation), a publisher URI, a year, etc. For articles published according to the long standing tradition of peer reviewed journals, there would also be information about the journal. On this level there should also be URIs to the actual content when dealing with digital objects like articles, ebooks, etc., no matter if access is free or restricted.
So far we have everything we need to know about publications “in the cloud”, or better: in a number of datastores available on a number of servers connected to the world wide web. This is more or less the situation described by OCLC’s Lorcan Dempsey in his recent post ‘Linking not typing … knowledge organization at the network level’. The only thing we need now is software to present all linked information to the user.
No libraries in sight yet. For accessing freely available digital content on the web you actually don’t need a library, unless you need professional assistance finding the correct and relevant information. Here we have identified a possible role of librarians in this new networked information model.
Now we have reached the interesting part: how to link local library data to this global shared model? We immediately discover that the original FRBR model is inadequate in this networked environment, because it implies a specific local library situation. Individual copies of a work (the Items) are directly linked to the Manifestation, because FRBR refers to the old local catalogue which describes only the works/publications one library actually owns.
In the global shared library linked data network we need an extra explicit level to link physical Items owned by the library or online subscriptions of the library to the appropriate shared network level. I suggest to use the “Holding” level. A Holding would have it’s own URI and contain URIs of the Manifestation and of the Library. A specific Holding in this way would indicate that a specific library has one or more copies (Items) of a specific edition of a work (Manifestation), or offers access to an online digital article by way of a subscription.
If a Holding refers to physical copies (print books or journal issues for instance) then we also need the Item level. An Item would have it’s own URI and the URI of the Holding. For each Item, extra information can be provided, for instance ‘availability’, ‘location’, etc. Local circulation administration data can be registered for all Holdings and Items. For online digital content we don’t need Items, only subscription information directly attached to the Holding.
Local Holding and Item information can reside on local servers within the library’s domain or just as well on some external server ‘in the cloud’.
It’s on the level of the Holding that usage statistics per library can be collected and aggregated, both for physical items and for digital material.
Now, this networked linked library data model still allows libraries to present a local traditional catalogue type interface, showing only information about the library’s own print and digital holdings. What’s needed is software to do this using the local Holdings as entry level.
But the nice thing about the model is that there will also be a lot of other options. It will also be possible to start at the other end and search all bibliographic metadata available in the shared global network, and then find the most appropriate library to get access to a specific publication, much like WorldCat does, but on an even larger scale.
Another nice thing of using triples, URIs and linked data, is that it allows for adding all kinds of other, non-traditional bibliographic links to the old inward looking library world, making it into a flexible and open model, ready for future developments. It will for instance be possible for people to discover links to publications and library holdings from any other location on the web, for instance a Wikipedia page or a museum website. And the other way around, from an item in local library holdings to let’s say a recorded theatre performance on YouTube.
When this new data and metadata framework will be in place, there will be two important issues to be solved:
- Getting new software, systems and tools for both back end administrative functions and front end information finding needs. For this we need efforts from traditional library systems vendors but also from developers in libraries.
- Establishing future roles for libraries, librarians and information professionals in the new framework. This may turn out to be the most important issue.