Mary E. Brown, Ph.D., Professor
Information Science

Southern Connecticut State University
501 Crescent Street, New Haven, CT 06515

Department of Information and Library Science
Fax: 1.203.392-5780 / Phone: 1.203.392-5781
Toll Free: 1-888-500-SCSU, then press 4

In this unit we ask two questions: What is a digital library? and What are its characteristics? In answering these questions we will learn about digital coherence, discuss the origins of digital libraries, and discover synonyms and metaphors for digital libraries. We will also touch on assumptions about a digital library, technologies of library collections, and the act of information seeking.

WHAT IS A DIGITAL LIBRARY?

Digital coherence

The term digital library has been applied to a wide variety of offerings from collections of electronic journals to software agents that support inquiry-based education to collections of email to electronic versions of a public library, to personal information collections, and even to the entire Internet. The one property these various entities have in common is their digitization or digital coherence (Daniel Atkins). Digital coherence means all the objects in a digital library, whether sounds, images, texts, or some other media, can be treated in essentially the same way. Prior to digital coherence, libraries needed to treat various media, for example, books, journals, videos, and musical recordings, differently (Harter, 1997). One could say that digital coherence is the mechanism which permits a form of equality among various information resources. This equality has importance for delivery and integration of information.

Envisioning a world brain and The Memex

The concept of a digital library is not new. In fact, the concept of digital libraries pre-dates the development of the first computer. H. G. Wells (circa 1938) was one of the first authors to write about th;0ce idea of a world brain that could supplement, add functionality to, and even replace traditional libraries. It is generally agreed that Vannevar Bush's 1945 article in the Atlantic Monthly, in which Bush conceives of a memex machine, inspired much of the early application of computers to information retrieval. The memex is a mechanical device based on microfilm technology. The concept of the memex included [a community of scholars indexing and creating] links between pieces of information in a [microfilm-based] research library combined with [microfilmed] personal notes (and classification system) and notes of colleagues (Lesk, 1997), anticipating the ideas of both hypertext and personal information retrieval systems (Harter, 1997).

Lesk (1997) assures us that by 2015 (70 years after Vannevar Bush published his memex dream) "we will have the equivalent of a major research library on each desk. And it will have searching capabilities beyond those Bush imagined" (p. 270).

Synonyms for the term digital library

In the early 1950s computers entered library services in the form of punched card applications in technical services operations and through the development of the MARC (MAchine-Readable Cataloging) standard for digitizing and communicating library catalog information (Harter, 1997). The vision of a fully computer-based library began to emerge in terminology in the mid-60s with J. C. R. Licklider's the library of the future. Over the years, other terms have been coined to refer to the concept of a digitized library, including electronic library, virtual library, library without walls, and bionic library, (Harter, 1997). Library science professor Winfred Lancaster extended this concept beyond the functions of the library, using the term paperless society. The use of the term digital library can be traced to the Digital Libraries Initiative, established through funding in 1994, by the National Science Foundation, the Advanced Research Projects Agency, and the National Aeronautics and Space Administration in the United States. Under this funding, six U.S. universities were granted a total of $24.4 million for digital library research. Two events motivated this funding: the sudden explosive growth of the Internet and the development of graphical Web browsers (Harter, 1997). These two developments significantly increased the viability of extending library resources and services beyond their current walls and communities, facilitating the sharing of scarce resources and the reaching of under-served populations.

Metaphors for digital libraries

There is little discussion or agreement in the literature about what constitutes a digital library. Harter (1997) juxtaposes two extreme views: the most inclusive view, which takes a digital library to be essentially what the Internet is today, and the metaphor of the traditional library. The essential differences between these two metaphors deal with their [presumed] properties of location, content, selection criteria, organization, authority control*, authorship, stability, access, and user groups, services and fees. The Internet has no physical or logical location; no quality control and no entry barriers; no organization scheme, authority control, or surrogates; no concept of author; and is fluid and transient. Everyone has access to the Internet, but access may require payment and purchase of equipment by the individual user. The traditional library is perceived to have their properties and no entry fee for the individual (Harter, 1997).

*Names of authors, variants of works (editions), and subject headings or descriptors are all controlled and common variants are cross-listed to the designated official form

WHAT ARE THE CHARACTERISTICS OF A DIGITAL LIBRARY?

Assumptions about a digital library

There are certain assumptions in discussions of a digital library. Levy and Marshall (1995) summarize these as: digital libraries are collections containing fixed , permanent documents which are based on digital technologies and are used by individuals working alone.

Fixity of content

The concept of a fixed and permanent document is based on the printed book: While a title may be reissued in a revised version, once a specific volume is printed and bound, it remains unchanged. Fixity creates a comfortable environment in which to perform certain library functions. Cataloguing practices have evolved around the largely fixed and permanent document. Fluid -- or -- transient documents, such as pamphlets and news clippings have been largely uncatalogued and stored in unclassified areas, such as the vertical file [cabinet]. The perception of lack-of-fixity in fluid digital documents, especially internet-based documents, leads to the assumption that digital items are ill-equipped for cataloguing and other library functions.

This concept of the fixity and permanence of a volume is, itself, flawed. For example, marginalia entered by the reader gives a book some degree of fluidity. Marginalia can contribute error-correction, critique, and even new content to the volume. Marginalia is viewed as an important addition to certain texts. (See, later in this work, discussion of marginalia in print-based and digital-based texts.) In addition to marginalia, vandalism-- such as removal of pictures or pages from a book--makes it difficult to predict that two books, identical at binding, still contain the same contents on any library shelf.

In classifying books as fixed and permanent, the ways of altering a book after issue have been dismissed. What has, in fact, been catalogued is the pristine just-off-the-press edition. Certainly, many digital-based texts could be archived as a pristine edition, with many fluid copies existing at other sites, and perhaps even linked to and from the archived edition. While the range of variation from a digital pristine copy would certainly have the potential to facilitate and exceed the variation from a print pristine copy, the practice of cataloging and archiving documents at certain points of development can extend to digital media. Fluid copies on the internet could be considered manuscripts in progress (just as some authors circulate paper-based working drafts of manuscripts to colleagues for reading, comment and use) and at some point a revised version could be catalogued and archived, not unlike revised editions of print-based texts.

This is a simplistic discussion of fixity in print and digital media, however, it does illustrate the point that fixity is a relative concept and does not necessarily belong exclusively to the print medium.

Technologies of library collections

The develop of the concept of a library based on digital technologies has revolved around the concept of a library based on the book. As Levy and Marshall (1995) point out, the book is not the only material contained in library collections. In addition to holdings of books, photographs, unbound and handwritten manuscripts and correspondents, and other ephemera which are adaptable to digital representation, libraries also contain three-dimensional artifacts, such as models, dioramas, toys and games, and realia--for example, a chameleon (for a borrow-a-pet service) or a wooden crate marked with 'Papers of [author]. Do not open until [date]. [Name of custodian or executor].' Realia and certain other three-dimensional items in a library's collection do not easily convert to digital format. Therefore, even if all currently convertible library materials were digitized, not all materials in the library would be in digital form.

The current concept of a digital library, then, is a subset of the larger concept of library, just as a video or a film library is a subset of the concept of library and not a substitute for it. While it is possible that certain libraries will collect only digital materials, it is more likely that libraries in general will make use of digital material where it best serves their patrons' needs and their libraries' budgets, much like libraries have used microforms and paperback editions. While some materials will not be suitable for digitalization, representations of these materials, such as the products of indexing and abstracting, will be. At some point in the future when applications such as virtual reality develop sufficiently, we may be able to satisfactorily convert much of the informational content of librariesU 3-D holdings to digital format. At least for now, a comprehensive library will of necessity be a multiple format collection.

The act of information seeking

The perception seems to be that the work in which the user engages in seeking information and the work in which the practitioner engages in supporting his or her patrons is a solitary act. Contrary to this impression, research finds that the library is a meeting place where collaborative work takes place among patrons, among practitioners, and between practitioners and patrons. For digital libraries to pattern the work capabilities of the traditional library, and to pattern the work habits of the library's patrons and practitioners, collaborative functionality must be included in digital library design. An exceptional example of progress toward this goal, the work of Robertson, Jitan and Reese (1997) of the US WEST Research & Information Group, is discussed later.

REFERENCES

Harter, S. (1997). Scholarly communication and the digital library: Problems and issues. Journal of Digital Information. http://jodi.ecs.soton.ac.uk

Levy, D. M. & Marshall, C. C. (1995.) Going digital: A look at assumptions underlying digital libraries. Communications of the ACM, 38(4), 77-84.

Robertson, S., Jitan, S., & Reese, K. (1997). Web-based collaborative library research. Proceedings of the 2nd ACM International Conference on Digital Libraries, 152-160.