Workshop on Electronic Texts · Library of Congress
SESSION III
Howard BESSER Networking Multimedia Databases What do we have to consider in building and distributing databases of visual materials in a multi-user environment? This presentation examines a variety of concerns that need to be addressed before a multimedia database can be set up in a networked environment. In the past it has not been feasible to implement databases of visual materials in shared-user environments because of technological barriers. Each of the two basic models for multi-user multimedia databases has posed its own problem. The analog multimedia storage model (represented by Project Athena's parallel analog and digital networks) has required an incredibly complex (and expensive) infrastructure. The economies of scale that make multi-user setups cheaper per user served do not operate in an environment that requires a computer workstation, videodisc player, and two display devices for each user. The digital multimedia storage model has required vast amounts of storage space (as much as one gigabyte per thirty still images). In the past the cost of such a large amount of storage space made this model a prohibitive choice as well. But plunging storage costs are finally making this second alternative viable. If storage no longer poses such an impediment, what do we need to consider in building digitally stored multi-user databases of visual materials? This presentation will examine the networking and telecommunication constraints that must be overcome before such databases can become commonplace and useful to a large number of people.
The key problem is the vast size of multimedia documents, and how this affects not only storage but telecommunications transmission time. Anything slower than T-1 speed is impractical for files of 1 megabyte or larger (which is likely to be small for a multimedia document). For instance, even on a 56 Kb line it would take three minutes to transfer a 1-megabyte file. And these figures assume ideal circumstances, and do not take into consideration other users contending for network bandwidth, disk access time, or the time needed for remote display. Current common telephone transmission rates would be completely impractical; few users would be willing to wait the hour necessary to transmit a single image at 2400 baud. This necessitates compression, which itself raises a number of other issues. In order to decrease file sizes significantly, we must employ lossy compression algorithms. But how much quality can we afford to lose? To date there has been only one significant study done of image-quality needs for a particular user group, and this study did not look at loss resulting from compression. Only after identifying image-quality needs can we begin to address storage and network bandwidth needs. Experience with X-Windows-based applications (such as Imagequery, the University of California at Berkeley image database) demonstrates the utility of a client-server topology, but also points to the limitation of current software for a distributed environment. For example, applications like Imagequery can incorporate compression, but current X implementations do not permit decompression at the end user's workstation. Such decompression at the host computer alleviates storage capacity problems while doing nothing to address problems of telecommunications bandwidth.
We need to examine the effects on network through-put of moving multimedia documents around on a network. We need to examine various topologies that will help us avoid bottlenecks around servers and gateways. Experience with applications such as these raise still broader questions. How closely is the multimedia document tied to the software for viewing it? Can it be accessed and viewed from other applications? Experience with the MARC format (and more recently with the Z39.50 protocols) shows how useful it can be to store documents in a form in which they can be accessed by a variety of application software. Finally, from an intellectual-access standpoint, we need to address the issue of providing access to these multimedia documents in interdisciplinary environments. We need to examine terminology and indexing strategies that will allow us to provide access to this material in a cross-disciplinary way. Ronald LARSEN Directions in High-Performance Networking for Libraries The pace at which computing technology has advanced over the past forty years shows no sign of abating. Roughly speaking, each five-year period has yielded an order-of-magnitude improvement in price and performance of computing equipment. No fundamental hurdles are likely to prevent this pace from continuing for at least the next decade. It is only in the past five years, though, that computing has become ubiquitous in libraries, affecting all staff and patrons, directly or indirectly.
During these same five years, communications rates on the Internet, the principal academic computing network, have grown from 56 kbps to 1.5 Mbps, and the NSFNet backbone is now running 45 Mbps. Over the next five years, communication rates on the backbone are expected to exceed 1 Gbps. Growth in both the population of network users and the volume of network traffic has continued to grow geometrically, at rates approaching 15 percent per month. This flood of capacity and use, likened by some to "drinking from a firehose," creates immense opportunities and challenges for libraries. Libraries must anticipate the future implications of this technology, participate in its development, and deploy it to ensure access to the world's information resources. The infrastructure for the information age is being put in place. Libraries face strategic decisions about their role in the development, deployment, and use of this infrastructure. The emerging infrastructure is much more than computers and communication lines. It is more than the ability to compute at a remote site, send electronic mail to a peer across the country, or move a file from one library to another. The next five years will witness substantial development of the information infrastructure of the network. In order to provide appropriate leadership, library professionals must have a fundamental understanding of and appreciation for computer networking, from local area networks to the National Research and Education Network (NREN). This presentation addresses these fundamentals, and how they relate to libraries today and in the near future.
Edwin BROWNRIGG Electronic Library Visions and Realities The electronic library has been a vision desired by many--and rejected by some--since Vannevar Bush coined the term memex to describe an automated, intelligent, personal information system. Variations on this vision have included Ted Nelson's Xanadau, Alan Kay's Dynabook, and Lancaster's "paperless library," with the most recent incarnation being the "Knowledge Navigator" described by John Scully of Apple. But the reality of library service has been less visionary and the leap to the electronic library has eluded universities, publishers, and information technology files. The Memex Research Institute (MemRI), an independent, nonprofit research and development organization, has created an Electronic Library Program of shared research and development in order to make the collective vision more concrete. The program is working toward the creation of large, indexed publicly available electronic image collections of published documents in academic, special, and public libraries. This strategic plan is the result of the first stage of the program, which has been an investigation of the information technologies available to support such an effort, the economic parameters of electronic service compared to traditional library operations, and the business and political factors affecting the shift from print distribution to electronic networked access. The strategic plan envisions a combination of publicly searchable access databases, image (and text) document collections stored on network "file servers," local and remote network access, and an intellectual property management-control system. This combination of technology and information content is defined in this plan as an E-library or E-library collection. Some participating sponsors are already developing projects based on MemRI's recommended directions.
The E-library strategy projected in this plan is a visionary one that can enable major changes and improvements in academic, public, and special library service. This vision is, though, one that can be realized with today's technology. At the same time, it will challenge the political and social structure within which libraries operate: in academic libraries, the traditional emphasis on local collections, extending to accreditation issues; in public libraries, the potential of electronic branch and central libraries fully available to the public; and for special libraries, new opportunities for shared collections and networks. The environment in which this strategic plan has been developed is, at the moment, dominated by a sense of library limits. The continued expansion and rapid growth of local academic library collections is now clearly at an end. Corporate libraries, and even law libraries, are faced with operating within a difficult economic climate, as well as with very active competition from commercial information sources. For example, public libraries may be seen as a desirable but not critical municipal service in a time when the budgets of safety and health agencies are being cut back. Further, libraries in general have a very high labor-to-cost ratio in their budgets, and labor costs are still increasing, notwithstanding automation investments. It is difficult for libraries to obtain capital, startup, or seed funding for innovative activities, and those technology-intensive initiatives that offer the potential of decreased labor costs can provoke the opposition of library staff.
However, libraries have achieved some considerable successes in the past two decades by improving both their service and their credibility within their organizations--and these positive changes have been accomplished mostly with judicious use of information technologies. The advances in computing and information technology have been well-chronicled: the continuing precipitous drop in computing costs, the growth of the Internet and private networks, and the explosive increase in publicly available information databases. For example, OCLC has become one of the largest computer network organizations in the world by creating a cooperative cataloging network of more than 6,000 libraries worldwide. On-line public access catalogs now serve millions of users on more than 50,000 dedicated terminals in the United States alone. The University of California MELVYL on-line catalog system has now expanded into an index database reference service and supports more than six million searches a year. And, libraries have become the largest group of customers of CD-ROM publishing technology; more than 30,000 optical media publications such as those offered by InfoTrac and Silver Platter are subscribed to by U.S. libraries. This march of technology continues and in the next decade will result in further innovations that are extremely difficult to predict. What is clear is that libraries can now go beyond automation of their order files and catalogs to automation of their collections themselves--and it is possible to circumvent the fiscal limitations that appear to obtain today. This Electronic Library Strategic Plan recommends a paradigm shift in library service, and demonstrates the steps necessary to provide improved library services with limited capacities and operating investments.
Text from Project Gutenberg, public domain in the United States.