Based upon our experience with map and imagery libraries in general, and upon our experience with the the GRIN project in particular, we believe that we already have useful initial characterizations of many user requirements. Below we indicate the nature of some of these requirements in terms of various classes of queries that we now know our system must support. These queries are intended to be typical of those asked by various classes of users in different domains.
Research-Level Spatial-Data Query. The first example indicates the steps that might be taken by a researcher in obtaining appropriate information. A faculty member (the user) is looking for supporting spatial information for ongoing anthropological research in the southern Venezuela-northern Brazil region. The user needs the spatial data to: make the existing research spatially accurate; to find out about any physical/environmental situations that would affect the indigenous population; and to tie the various research pieces together. The exact area is known, so the user uses a graphic front end that will display a map of the general area, upon which the area of interest can be drawn. Depending on the topics of interest - rainfall, soils, vegetation, topography, hydrography - a general search that pulls up multiple subjects and multiple formats is performed. The users request will go out over the Internet to distributed databases on Amazonia. The system performs the search and then returns information back to the user, which identifies a number of parameters of the requested data. The user refines and redirects the query to pinpoint the exact points of interest, by also making use of the metadata, browsable images, text, and other information provided by the system.
Undergraduate Spatial-Data Query: A class on the history of religion is given an assignment to locate on a map approximately 50 place names; these place names include both cultural and physical features, both current and ancient. Each student is expected to work up a map, using the system. First, the student calls up the map of the area, and puts it into a personal-map window. Next, the student calls up the names, one by one, by querying the thesaurus. As each name is called up, the student requests that the place be plotted on the map in the personal-map window. Then the personal map is written to a file and printed out. The student then searches on a archeological-digs slide database; searches for each archeological site by name, and then browses the "slides" of that site.
K-12 Community Spatial-Data Query: A high-school teacher is putting together a module for 8th-grade students to study the local ecosystem. The teacher asks first for any materials highlighting natural science subjects and discovers that many are of the local slough. He then refines the search for all information on the local slough to build a source list for the students.
Public Library Spatial-Data Queries: There are a wide variety of queries that one must expect to support at public libraries. We give a few examples:
An environmental consultant is constructing an impact statement for
a client, that will satisfy state regulations governing hazardous
materials to expedite the transfer of real property:
historical photos and maps to evaluate the property's use over
time are required.
A person is preparing a grant application applying for state funds
for the construction of day-care facilities in the city of St.
Louis: To provide documentation for the need for such facilities,
the person needs georeferenced data such the location of areas in
the city of St. Louis with the largest concentration of children
under five and with female heads of households.
Users seeking genealogy information are tracking down their past
ancestry: In order to do this, they need to find out about
everything from eighteenth-century Polish village place names to
cemetery locations in Virginia. Situations where the user is dealing
with places that have changed name, non-Roman alphabet names, and
names about which the patron is unsure of spelling or country of
location are all very common.
People with a strong interest in the local history
of a given area: who were the
different owners of property over the years? What sort of
businesses were ever on the property?
Librarians' spatial data queries: A different perspective is that of managing spatial data. Library staff dealing with such data need efficient, quick methods of maintaining sheet/frame-level control. This control is used for inventorying of collections and completing partial sets. For example, it has been proposed that the index maps to map series held at the Library of Congress's Geography and Map Division be standardized and put into electronic form. This would provide system users with holdings information of multi-item sets. To maximize purchasing power, librarians seek to minimize redundancy in holdings amongst sister libraries. Thus they frequently need to know at how many different libraries and which libraries a given set of data or a publication is held. For standard book-format material, finding this information is relatively simple. However, even in the last 20 years, spatial data has not been sufficiently catalogued. For example, it can be very difficult and time-consuming to discover which libraries have an 1894 edition of a sheet of the British Ordnance Survey's 1:63,360-scale series.