APPENDIX F: RELATED WORK: THE ALEXANDRIA DIGITAL LIBRARY
PROJECT AND ON-LINE ACCESS TO INFORMATION VIA GEOGRAPHICAL
REFERENCES
TARI WEICHERDING, UNIVERSITY OF ILLINOIS
Management of geospatial data is an emerging challenge for academia, government
agencies, and private companies. Several new geospatial data systems and related tech-
nologies are under development to address such changes.
One such program is the Alexandria Digital Library Project, which is one of six proj-
ects funded under the Digital Libraries Initiative (DLI), a joint program of the National
Science Foundation, the Defense Advanced Research Projects Agency (DARPA), and the
National Aeronautics and Space Administration. The Alexandria Project, which is based
at the University of California, Santa Barbara (UCSB), brings together a unique blend of
researchers, developers, and educators, spanning the academic, public, and private sec-
tors. The goal of this project is to build a distributed digital library (DL) that allows users
to access and manipulate information in a variety of classes of collection items in terms
of geospatial reference.
The Alexandria Project's research and development accomplishments achieved as of
July 1998 include
The development and implementation of a new, three-tier architecture for ADL,
including a Java client, HTTP middleware involving five standard interfaces to allow
the easy construction of new clients, and two heterogeneous databases (catalog and
gazetteer)
Redesign of the user interface based on input from a series of evaluation studies that
includes context-sensitive help
Incorporation of instrumentation technology into the testbed to support and facilitate
evaluation
Incorporation of significant collections into the testbed
Interfacing ADL with various external applications, such as a computational mod-
eling system, image processing systems, and a collaborative desktop environment,
using wrapper technology
Agreements with the California Digital Library (CDL) to incorporate ADL in the
first release of CDL before the end of 1998
Numerous research contributions in the areas of access to information by georeference,
distributed database support, image processing and access, high-performance and
parallel computing support, and user evaluation (http://www.alexandria.ucsb.edu/).
A geospatial information research team working on the Alexandria Project, compris-
ing Goodchild (leader), Carver, Geffner, Hill, Kemp, Kothuri, Larsgaard, and Smith, is
responsible for investigating a variety of issues relating to the integration of spatially ref-
erenced information objects into ADL. Because of its focus on geographic data, ADL
has encountered and addressed several issues that arise in this context. The transition to
a digital world has significant impact on many of the conventions associated with geo-
graphic data, on arrangements for data production and dissemination, and on the ways in
which data are used. During the past year, ADL has made significant progress on many
issues such as the level of geographic detail, fuzzy footprints, the geolibrary, support for
geocomputation, and libraries as central services.
First of all, many geographic phenomena are almost infinitely complex, so any attempt
to capture them in geographic data must involve approximation. The level of detail of a
data set is an important indicator of its volume, and thus of many practical issues of stor-
age and dissemination. Within ADL, level of detail is a major determinant of the prob-
lems the user will encounter in attempting to decide whether a dataset meets the user's
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