by Eleta Exline
During last week’s lively discussion and group editing of our strategic plan a question was asked about the differences between Digital Libraries and Institutional Repositories. For those of you who weren’t able to attend or who would appreciate an expanded (and possibly more coherent!) explanation, I am submitting a two-part article for your perusal.
Part 1: Digital Libraries
In practice, digital libraries are often viewed as an extension of traditional library collections. They usually contain digitized materials from the library’s paper or analog collections, and are often drawn from rare books collections, special collections, archives, or otherwise highlight the particular strengths of a given library. Digital library collections have focused on these types of materials because digital formats are an ideal access medium for items too fragile to withstand repeated handling, materials too rare to circulate, and formats awkward to handle and manipulate in the original, such as large maps. When appropriate standards are used for digitizing, structuring, and describing these materials, digital libraries can be considered analogous to other preservation reformatting and distribution processes, such as microfilm. The digital library concept can be expanded to include materials in any digital format, including sound, video, multi-media, “born-digital” (resources that were originally created in an electronic environment), data sets, computer programs, and licensed content such as e-books and art images purchased from vendors.
Digital library collections are most often stored in Digital Asset Management Systems (DAMS), which are specialized storage and retrieval systems that support digital formats and metadata. Metadata for digital collections is typically repurposed from existing records in library catalogs (when they exist) or is created by library personnel, much as other library materials are cataloged. The proliferation of digital libraries has inspired a parallel proliferation of metadata standards that are used not only describe the digital content, but also provide its structure and enable its management (Read more about metadata). Some storage and delivery systems offer opportunities for enhanced functionality such as full-text searching and image manipulation, allowing users to interact with library resources in ways not previously possible. The UNH Library currently uses DigiTool as our DAMS.
Because far-flung resources can be gathered together into one digital library system that can be accessed on the Internet from any physical location, digital collection building lends itself to collaboration. Collaborative projects, often state or region focused, allow multiple institutions, including those that might not have the resources or infrastructure to build their own online collections, to create stronger, more comprehensive, and more diverse digital libraries than it is possible for most single institutions to do on their own. Examples include the California Digital Library and the New Jersey Digital Highway. Another method for gathering together dispersed digital materials is to harvest the metadata from multiple collections into a single database that can be searched – the digital material is then delivered from its “home” system. University of Michigan maintains the OAIster project, which harvests metadata from hundreds of digital libraries using the Open Archives Initiative – Protocol for Metadata Harvesting (OAI-PMH)
Another type of collaboration to build large-scale digital libraries has emerged over the past several years. With the development of such projects as the Google Book Library Project and the Open Content Alliance (OCA), mass digitization is quickly making vast amounts of library content available in digital formats. Mass digitization has been driven in part by the development of cheaper and less destructive scanning techniques, less expensive storage space, competition among online search providers, and user demand spurred by the ubiquitous availability of networked access to information of all types. In these projects, libraries provide the materials and the project organizer provides scanning, storage and delivery. As part of the Boston Library Consortium, the UNH Library is participating in the OCA project, thus many of our out-of-copyright books are now available at the Internet Archive. The OCA project allows us, and any other user of the materials, to download copies. This means that we can archive the OCA scanned books in our digital library, offering two points of access to potential users.
For many examples of digital libraries, visit our own Guide to Digital Collections.
Part 2: Institutional Repositories (coming soon)