Interest in ontologies has grown rapidly in recent years due to the adoption of an increasingly semantic web. The web is by no means the only place where ontologies may be implemented, but it is the use of ontologies on the semantic web that is the primary focus of this book, as they have the greatest potential, and as such are likely to be of greatest interest to the modern library and information professional.
The chapter starts with an introduction to the semantic web and its most recent incarnation as linked data, before considering more closely the standards that have been adopted for structuring the semantic web. Finally, the last part of the chapter looks at how ontologies have been increasingly adopted in a wide variety of libraries as well as other cultural heritage institutions and commercial organizations.
The semantic web and linked data
The semantic web is about moving from a web of documents to a web of data, from one that is primarily designed to be read by humans to one that can be read by machines. It first started gaining widespread attention in 2001 with publications in Nature (Berners-Lee and Hendler, 2001) and Scientific American (Berners-Lee, Hendler and Lassila, 2001). The web has put vast quantities of information at our fingertips, but much of this information is unstructured and it requires a lot of effort to gather and analyse the information resources that we need. For a simple informational query we pay little attention to the effort required. If we want to know what time a show starts it is generally simple enough to enter the name of the theatre and browse the pages for show times. But as queries require collecting data from multiple sites, the task can quickly become arduous. Wanting to know which shows are playing in a five-mile radius of where I am and which start after 8p.m. would require aggregating information of multiple sites, or at least visiting a site that had aggregated that information on my behalf. Some types of information have many aggregating sites (e.g., hotel and holiday information), but there is a vast amount of information that may not be commercially viable for aggregation.