Definitions History Digital Library Projects Motives for Digital Libraries The Cost Issue
Hardware and Software Requirements Storage Requirements Document Conversion
Conversion Cost Comparisons Calculating Implementation Costs Worksheet 1. An Example of a Text-Based Implementation
Hardware and Software Requirements Storage Requirements Document Conversion Calculating Implementation Costs Worksheet 2. An Example of an Image-Based Implementation
TABLES 1. Storage capacities of selected optical disk autochangers 2. Data-entry time per 1,000 characters at various keystroking rates 3. Data-entry costs per 1,000 characters without verification and error correction 4. Data-entry cost per 1,000 characters including keystroke verification and correction 5. Data-entry cost per 1,000 characters including sight verification and correction 6. Comparison of document conversion costs: Example 1 7. Comparison of document conversion costs: Example 2 8. Comparison of document conversion costs: Example 3 9. Comparison of document conversion costs: Example 4 10. Image storage requirements for test documents scanned at 200 dpi 11. Image storage requirements for test documents scanned at 300 dpi 12. Storage capacities of selected optical disk autochangers for documents scanned at 200 dpi 13. Storage capacities of selected optical disk autochangers for documents scanned at 300 dpi 14. Comparison of costs for document conversion by in-house scanning and service bureaus
Broadly defined, a digital library is a collection of computer-processible information or a repository for such information. In nonlibrary applications, the phrase has been widely applied to centralized repositories of computer programs or machine-readable data. That usage has a long history, particularly in scientific and technical applications. Gerstenberg (1977), for example, describes a digital library of photonuclear data maintained by the National Bureau of Standards. More recently, Schatz (1991, 1994) has discussed a digital library of scientific information about C elegans, a nematode worm that serves as a model organism in molecular biology. Allen (1993) describes a similar application in botany. Coyne and Hulen (1993) and Coyne et al. (1994) discuss the role of the National Storage System Foundation (NSSF) in promoting digital libraries as repositories of the nation's information assets. Information management specialists, policy makers, and politicians increasingly view such repositories as important components of an emerging National Information Infrastructure (NII), a concept discussed by Altinkemer et al. (1994), Baron (1994), Doctor (1994), Doty and Bishop (1994), Forcht and Oeare (1994), Galbreath and Andreotta (1994), Hayashi and Sueyoshi (1994), McKeown (1994), Pelton (1994), Radack (1994), Shuler (1993), and Williams (1994), among others. Other publications that equate digital libraries with large information repositories include Berleant and Berghel (1994), Drapeau et al. (1994), and Gladney (1993). Various online databases and CD-ROM information products, particularly those with multimedia or interactive video components, are characterized by their producers as "digital libraries." Alternatively, the phrase "digital libraries" may denote the computer storage devices on which information repositories reside; optical disk jukeboxes and magnetic tape autoloaders, for example, are sometimes characterized as digital libraries.
Definitions employed in library literature are comparably broad. Citing various congressional bills and national policy documents, Fox (1993) and Fox and Lunin (1993) equate digital libraries with computerized, networked library systems. Garrett (1993), Garrett and Lyons (1993), and Lynch (1991) use the phrase to describe databases, including library catalogs, that are accessible through the Internet or the emerging National Research and Education Network (NREN). …