Benefits of the Linked Data Approach
The Linked Data approach offers significant advantages over current practices for creating and delivering library data while providing a natural extension to the collaborative sharing models historically employed by libraries. Linked Data and especially Linked Open Data is sharable, extensible, and easily re-usable. It supports multilingual functionality for data and user services, such as the labeling of concepts identified by a language-agnostic URIs. These characteristics are inherent in the Linked Data standards and are supported by the use of Web-friendly identifiers for data and concepts. Resources can be described in collaboration with other libraries and linked to data contributed by other communities or even by individuals. Like the linking that takes place today between Web documents, Linked Data allows anyone to contribute unique expertise in a form that can be reused and recombined with the expertise of others. The use of identifiers allows diverse descriptions to refer to the same thing. Through rich linkages with complementary data from trusted sources, libraries can increase the value of their own data beyond the sum of their sources taken individually.
By using globally unique identifiers to designate works, places, people, events, subjects, and other objects or concepts of interest, libraries allow resources to be cited across a broad range of data sources and thus make their metadata descriptions more richly accessible. The Internet's Domain Name System assures stability and trust by putting these identifiers into a regulated and well-understood ownership and maintenance context. This notion is fully compatible with the long-term mandate of libraries. Libraries, and memory institutions generally, are in a unique position to provide trusted metadata for resources of long-term cultural importance as data on the Web.
Another powerful outcome of the reuse of these unique identifiers is that it allows data providers to contribute portions of their data as statements. In our current document-based ecosystem, data is exchanged always in the form of entire records, each of which is presumed to be a complete description. Conversely, in a graph-based ecosystem an organization can supply individual statements about a resource, and all statements provided about a particular uniquely identified resource can be aggregated into a global graph. For example, one library could contribute their country's national bibliography number for a resource, while another might supply a translated title. Library services could accept these statements from outside sources much as they do today when ingesting images of book covers. In a Linked Data ecosystem, there is literally no contribution too small -- an attribute that makes it possible for important connections to come from previously unknown sources.
Library authority data for names and subjects will help reduce redundancy of bibliographic descriptions on the Web by clearly identifying key entities that are shared across Linked Data. This will also aid in the reduction of redundancy of metadata representing library holdings.
Benefits to researchers, students, and patrons
It may not be obvious to users of library and cultural institution services when Linked Data is being employed because the changes will lie "under the hood." As the underlying structured data becomes more richly linked, however, the user may notice improved capabilities for discovering and using data. Navigation across library and non-library information resources will become more sophisticated. Federated searches will improve through the use of links to expand indexes, and users will have a richer set of pathways for browsing.
Linked Data builds on the defining feature of the Web: browsable links (URIs) spanning a seamless information space. Just as the totality of Web pages and websites is available as a whole to users and applications, the totality of datasets using RDF and URIs presents itself as a global information graph that users and applications can seamlessly browse by resolving trails of URI links ("following one's nose"). The value of Linked Data for library users derives from these basic navigation principles. Links between libraries and non-library services such as Wikipedia, Geonames, musicbrainz, the BBC, and The New York Times will connect local collections into the larger universe of information on the Web.
Linked Data is not about creating a different Web, but rather about enhancing the Web through the addition of structured data. This structured data, expressed using technologies such as RDF in Attributes (RDFa) and microdata, plays a role in the crawling and relevancy algorithms of search engines and social networks, and will provide a way for libraries to enhance their visibility through search engine optimization (SEO). Structured data embedded in HTML pages will also facilitate the re-use of library data in services to information seekers: citation management can be made as simple as cutting and pasting URIs. Automating the retrieval of citations from Linked Data or creating links from Web resources to library resources will mean that library data is fully integrated into research documents and bibliographies. Linked Data will favor interdisciplinary research by enriching knowledge through linking among multiple domain-specific knowledge bases.
Migrating existing library data to Linked Data is only a first step; the datasets used for experiments reported in a paper and the model used by the authors to process that data can also be published as Linked Data. Representing a paper, dataset, and model using appropriate vocabularies and formalisms makes it easier for other researchers to replicate an experiment or to reuse its dataset with different models and purposes. If adopted, this practice could improve the rigor of research and make the overall assessment of research reports outlined in research papers more transparent for easier validation by peers. (See for instance the Enhanced Publications use case.)
Benefits to organizations
By promoting a bottom-up approach to publishing data, Linked Data creates an opportunity for libraries to improve the value proposition of describing their assets. The traditionally top-down approach of library data -- i.e., producing MARC records as stand-alone descriptions for library material -- has been enforced by budget limits: libraries do not have the resources needed to produce information at a higher level of granularity. With Linked Data, different kinds of data about the same asset can be produced in a decentralized way by different actors, then aggregated into a single graph.
Linked Data technology can help organizations improve their internal data curation processes and maintain better links between, for instance, digitized objects and their descriptions. It can improve data publishing processes within organizations even where data is not entirely open. Whereas today's library technology is specific to library data formats and provided by an Integrated Library System industry specific to libraries, libraries will be able to use mainstream solutions for managing Linked Data. Adoption of mainstream Linked Data technology will give libraries a wider choice in vendors, and the use of standard Linked Data formats will allow libraries to recruit from and interact with a larger pool of developers.
Linked Data may be a first step toward a "cloud-based" approach to managing cultural information -- one which could be more cost-effective than stand-alone systems in institutions. This approach could make it possible for small institutions or individual projects to make themselves more visible and connected while reducing infrastructure costs.
With Linked Open Data, libraries can increase their presence on the Web, where most information seekers may be found. The focus on identifiers allows descriptions to be tailored to specific communities such as museums, archives, galleries, and audiovisual archives. The openness of data is more an opportunity than a threat. Clarification of the licensing conditions of descriptive metadata facilitates its reuse and improves institutional visibility. Data thus exposed will be put to unexpected uses, as in the adage: “The best thing to do to your data will be thought of by somebody else.”
Benefits to librarians, archivists, and curators
The benefits to patrons and organizations will also have a direct impact on library professionals. By using Linked Open Data, libraries will create an open, global pool of shared data that can be used and re-used to describe resources, with a limited amount of redundant effort compared with current cataloging processes.
The use of the Web and Web-based identifiers will make up-to-date resource descriptions directly citable by catalogers. The use of shared identifiers will allow them to pull together descriptions for resources outside their domain environment, across all cultural heritage datasets, and even from the Web at large. Catalogers will be able to concentrate their effort on their domain of local expertise, rather than having to re-create existing descriptions that have been already elaborated by others.
History shows that all technologies are transitory, and the history of information technology suggests that specific data formats are especially short-lived. Linked Data describes the meaning of data ("semantics") separately from specific data structures ("syntax" or "formats"), with the result that Linked Data retains its meaning across changes of format. In this sense, Linked Data is more durable and robust than metadata formats that depend on a particular data structure.
Benefits to developers and vendors
Library developers and vendors will directly benefit from not being tied to library-specific data formats. Linked Data methods support the retrieval and re-mixing of data in a way that is consistent across all metadata providers. Instead of requiring data to be accessed using library-centric protocols (e.g., Z39.50), Linked Data uses well-known standard Web protocols such as the Hypertext Transport Protocol (HTTP).
Developers will also no longer have to work with library-specific data formats, such as MARC, which require custom software tools and applications. Linked Data methods involve pushing data onto the Web in a form that is generically understandable. Library vendors that support Linked Data will be able to market their products outside of the library world, while vendors outside the library world may be able to adapt their more generic products to the specific requirements of libraries. By leveraging RDF and HTTP, library developers are freed from the need to use domain-specific software, opening a growing range of generic tools, many of which are open-source. They will find it easier to build new services on top of their data. This also opens up a much larger developer community to provide support to information technology professionals in libraries. In a sea of RDF triples, no developer is an island.