The purpose of a digital library is to provide coherent organization andconvenient access to typically large amounts of digital information. Thefollowing principles provide working definitions of a digital library from botha conceptual and a practical standpoint:
Digital library systems compose a family of automated systems that togetherprovide a comprehensive capability to manage the digital content of anenterprise. It is useful to divide the capabilities of digital library systemsinto the following areas:
Content exists in multiple sizes, formats, and media, each with accompanyingtechnical challenges. Content may be structured or unstructured. It may haveexact, precise meaning; or it may be fundamentally ambiguous. Content maydirectly or indirectly support a business process or function.
A digital library architecture shows how capabilities are realized andrelated, and does this at several levels. Digital library architectures showhow business processes or functions are enhanced; they show how technologycomponents fit together and how, in detail, components interoperate with eachother.
Such functions and relationships, when reduced to a particular software andhardware implementation, lead to operational digital library systems.
Digital library functions, insofar as they purport to organize information,may be compared with traditional library functions. Consider digitization,which technically is the conversion of analog to digital formats. A commonhuman artifact, such as a bound book, loses value when simply scanned intobits. In a library context, where organization, access, protection, andpreservation are important business functions, digitization technologies arestarting points for a complicated set of computational processes that in thefirst instance reconstruct the cultural, conventional, and intuitivesignificance, structure, and external relationships that defined the originalartifact. Additionally, digitization and other processes may be able to addvalue and support certain fiduciary responsibilities that resemble functions oftraditional libraries.
In a similar way, other core capabilities of traditional libraries can betransposed to the digital domain. Cataloging is transposed to the generation ofmetadata, and is an area where much work needs to be done to develop automated,multidimensional indexing and cataloging procedures. Just as the public cardcatalog is a gateway to the holdings of a conventional library, search ofcontent and metadata is the gateway to a digital library. Circulation in aconventional library transposes to network access, retrieval and delivery.
The fiduciary responsibilities of traditional libraries are related toissues of copyright protection and intellectual property rights. Table 4.1relates digital library capabilities to well-known capabilities of traditionallibraries. The point is that traditional libraries have established uniformbusiness processes and highly interoperable data formats which supportespecially bibliographic catalogs, item ordering, and interlibrary loan.Although many of these procedures pre-date "digital" libraries, digital librarydesign can benefit from the comparisons.
Digital Library Capability
Traditional Library Capability
Acquisitions and collection development
Catalog and Index
Cataloging rules and bibliographic control
Stacks, inventory management and shelf lists
Public card catalog
Patron privileges and circulation rules consistent with publiclaw and policy
Loan management and interlibrary loans
Having made these comparisons, it must be emphasized that neither in theUnited States nor in Japan is the digital library regarded as a technologyrelated to library automation or the provision of integrated library systemsfor operating traditional libraries. None of the digital library projectsvisited in Japan either utilized or were based on library automationtechnologies. On the contrary, the panel saw digital library technologies,which very strikingly enabled the digital library capabilities enumerated inthis chapter, creating new lines of business in both public and privateendeavors.