Introduction
As the nature and form of the library catalogue has evolved over time, so has the definition of library resources. In fact, the term ‘resources’ used in this context is a relatively recent development, as traditionally library assets have been referred to as ‘materials’. While the word ‘materials’ is broader in scope than terms for specific things managed by libraries, such as books, journals or DVDs, it still implies a physicality that no longer accurately reflects the wide array of resources managed by libraries, particularly research libraries. Most large research libraries, and many smaller libraries, especially those associated with more recently established academic institutions, allocate a significant proportion of their budgets towards licensed electronic content, including e-books and journals. These resources not only lack a physical embodiment, but they are often not even owned by the library. The library pays for access to the content, but the access is typically not perpetual and can change over time.
The increased scope of web-scale library discovery systems leads us to further reconsider the definition of library resources, and what we provide access to in the catalogue. Along with all the physical and electronic resources managed by the library, additional content provided by users or third parties can be made accessible, as well as a multitude of other services. Should libraries include information about these services within the discovery system? What are the best methods for doing this, and what challenges does this present for the management of metadata?
From catalogue to discovery system
The original library catalogues took several different forms, beginning as books and scrolls inventorying the contents of an individual library's physical collection. These evolved into the nearly ubiquitous card catalogue, which was the primary format from the late 19th century through the 1970s. It is probably safe to say that when online public access catalogues began to emerge in the 1980s, most librarians did not anticipate the multitude of ways in which the continuing development of information technology would force them to completely rethink the role and purpose of the library catalogue. Initially, OPACs sought to replicate as much as possible the features of the card catalogue, in providing an inventory of materials physically held by the library, and allowing users to search by browsing indexes of authors, titles and subjects.