Alexandria Digital Library Project Research Articles

The alexandria digital library project: Review, assessment, and prospects

The alexandria digital library project: Review, assessment, and prospects

The Alexandria Digital Library architecture

Since 1994, the Alexandria Digital Library Project has developed three prototype digital libraries for georeferenced information. This paper describes the most recent of these efforts, a three-tier client-server architecture that relies heavily on a middleware layer to present a single uniform set of interfaces to multiple heterogeneous servers. These standard interfaces, all of which are implemented in HTTP, support session management, collection discovery and evaluation, metadata searching, metadata retrieval, and online holding retrieval. An XML-based metadata encoding scheme and a simple Boolean query language have also been developed. The architecture described by these interfaces has been implemented at UCSB.

Usability Evaluation of Digital Libraries

Summary This paper distinguishes evaluation procedures in a physical library from those in a digital library, reviewing usability evaluation work within a taxonomy of system design, development and deployment. Usability evaluation of digital libraries should follow two evaluation strategies. The first a convergent methods paradigm. Evaluation data are collected throughout the system life cycle using several different methods. Where comparable interpretations result, evaluators can make confident recommendations for system revision. A second strategy assesses not only the digital library, but the evaluation methods themselves. This self-referring analysis is termed a “double-loop paradigm” and allows evaluators to identify relative efficacy of particular assessment methods for specific library situations. The paper will present evidence for adopting these two strategies, drawing upon the user evaluation effort for the Alexandria Digital Library Project.

Scalable access within the context of digital libraries

This paper presents a summary of some of the work-in-progress within the Alexandria Digital Library Project. In particular, we present scalable methods of locating information at different levels within a distributed digital library environment. Starting at the high level, we show how queries can be routed to appropriate information sources. At a give a source, efficient query processing is supported by using materialized views and multidimensional index structures. Finally, we propose solutions to the problem of storage and retrieval of large objects on secondary and tertiary storage.

Alexandria Digital Library

The goal of the Alexandria Digital Library Project is to develop a distributed system that provides a comprehensive range of library services for collections of spatially indexed and graphical information. While such collections include digitized maps and images as important special components, the Alexandria Digital Library will involve a very wide range of graphical materials and will include textual materials. Users of the Alexandria Digital Library will range from school children to academic researchers to members of the general public. They will be able to retrieve materials from the library on the basis of information content as well by reference to spatial location.