The catalog component of ADL permits users to make a mapping from their requirements for information to the most appropriate set of information accessible from the total collection of items. The standard cataloging system of an analog library, including the usual author and subject catalogs, provides an initial model for the catalog component of DLs. It is necessary, however, to generalize this model for DLs, such as ADL, that contain spatially-indexed materials.
The catalog component of the RP incorporated
a generalization based on a new metadata schema
for spatially-indexed information that combines
the Federal Geographic Data Committee (FGDC)
and USMARC standards [5]
.
The design and implementation of the WP catalog represents a
further step in this process of generalization
in which we introduce metadata that supports
new classes of content-based queries.