The Importance of Location
From pirate maps to GPS (Global Positioning System) units in cars, where we’re going and where we’ve been all revolve around places. Much as taxonomists use scientific names as identifiers for the rich complexity of an organism’s genetic footprint, most of us talk in terms of place names rather than in the more spatially exact terms of latitude and longitude coordinates. Linda Hill, of the Alexandria Digital Library writes, “Place-names are used in discourse and text, subject headings and index terms, labels on maps, and to identify administrative districts for addresses, statistics, and data. Geospatial coordinates are used to represent the location of features on the surface of the Earth and the coverage of maps, aerial photographs, remote-sensing images, and datasets of various kinds.” ¹

In the past, and even now for many purposes, the inexactness of place names is functional, but precludes us from effectively integrating the textual and spatial information universes. As society becomes increasingly complex, and multiple and often conflicting human activities demand equal space, exactitude of location takes on a critical function.

Emergency preparedness issues have forced all communities to take an active role in preparing plans that accurately show where key resources (hospitals, power plants, etc.) are located. Prior to this escalated national initiative, governmental and non-governmental organizations were finding it increasing desirable to pinpoint the spatial, or geographic, footprint of various kinds of data collections.

In the library world, geographic visualization is becoming a defining functionality in digital library collections. Gregory Crane, Perseus Project, Tufts University, writes, “In a mature digital library (DL), documents should coexist with a Geographic Information System (GIS). The GIS component of the DL should be able to scan documents for toponyms and then generate a map illustrating the places cited in a document.” ² Of equal importance is the conceptualization and development of distributed geolibraries. The National Research Council defines a geolibrary as “a digital library filled with geoinformation—information associated with a distinct area or footprint on the earth’s surface—and for which the primary search mechanism is place. A geolibrary is distributed if its users, services, metadata, and information assets can be integrated among many distinct locations.” ³

Library Traditions of Geographic Access
MARC records may contain several geographic access points. Classification numbers may include coding for place. Traditionally, map catalogers have entered latitude and longitude coordinates in the 034 field (coded cartographic data) and 255 field (cartographic mathematical). The most familiar access is through geographic names found in the 651 subject fields.

Geographic Subject Headings
The Library of Congress Subject Headings (LCSH) approach most geographic issues from an administrative unit focus. Michael Buckland comments, “The names, the boundaries, and the political structures of these entities tend to be unstable over time. This situation is generally acceptable for current affairs and political topics, but provides limited help for scientific, historical, and narrowly local searches when the interest is in geographical region (space) rather than geopolitical unit.” ⁴

The Geographic Names Information System (GNIS) is the official authority for all U.S. government agencies and is maintained by the U.S. Geological Survey under the auspices of its Board of Geographic Names. Although catalogers draw on GNIS as the primary authority for U.S. place names, they have never systematically included the latitude/longitude coordinates found in the GNIS database. Also, although it seems counterintuitive, when catalogers use other resources to create U.S. place name entries, they do not submit them to GNIS. GNIS and its companion GEOnet (foreign names database) serve as core data sets for all of the well-known digital gazetteer initiatives: Alexandria Digital Library, Getty Thesaurus of Geographic Names, etc.

Spatial Coordinates
Spatial coordinates (latitude/longitude pairs) are used to identify the exact location of features on the Earth’s surface. Coordinates define features with points, bounding boxes, or polygons. As noted above, the spatially more exact 034 and 255 fields have been seen as the domain of map catalogers. Hill states, “it is not current practice to use these fields to catalog documents such as environmental impact reports that are also explicitly associated with coordinate-defined locations.” ⁵

Spatial searching either by lat/long or through a graphical map interface appears to be very limited in the bibliographic world. The National Oceanic and Atmospheric Administration (NOAA) library catalog and NOAA’s Coral Reef Information System are searchable by bounding box coordinates. The reef literature also has a map interface. Additionally, the National Geospatial-Intelligence Agency library catalog and Princeton’s Geosciences and Map Library catalog GEOMAP [not accessible in late November 2004] are purported to be coordinate friendly. GEOREF, the abstracting service of the American Geological Institute, has also enabled bounding box coordinate searching.

Geographic Access in Non-MARC Metadata
The impetus for creating rigorous geospatial metadata came in 1994 with President Clinton’s issuance of Executive Order 12906: COORDINATING GEOGRAPHIC DATA ACQUISITION AND ACCESS: THE NATIONAL SPATIAL DATA INFRASTRUCTURE, which states:

Geographic information is critical to promote economic development, improve our stewardship of natural resources, and protect the environment. Modern technology now permits improved acquisition, distribution, and utilization of geographic (or geospatial) data and mapping. The National Performance Review has recommended that the executive branch develop, in cooperation with State, local, and tribal governments, and the private sector, a coordinated National Spatial Data Infrastructure to support public and private sector applications of geospatial data in such areas as transportation, community development, agriculture, emergency response, environmental management, and information technology. ⁶

This Executive Order led to the establishment of the Federal Geographic Data Committee (FGDC) with the mission to minimize the duplication of effort and cost in collecting data sets. To accomplish that mission, a Content Standard for Digital Geospatial Metadata (CSDGM)(FGDC-STD-001-1998) was developed with an associated metadata clearinghouse. The standard was to be used by all U.S. governmental agencies for sharing information with others on the data they were collecting.

Geographic elements in the Digital Geospatial Metadata are defined by latitude and longitude coordinates. The same geographic approach is used by the National Biological Information Infrastructure in its Content Standard for Digital Geospatial Metadata, Part 1: Biological Data Profile, by the Bathymetric Subcommittee in its Metadata Profile for Shoreline Data (FGDC-STD-001.2-2001), and in the remote sensing community in its Content Standard for Digital Geospatial Metadata: Extensions for Remote Sensing Metadata.

Currently, FGDC is being harmonized with ISO 19115, the metadata part of the ISO 19100 family of standards entitled Geographic Information/Geomatics. The ISO standard provides for the inclusion of polygons and bounding boxes in the metadata. Kresse and Fradaie provide a complete description in their ISO Standards for Geographic Information. ⁷

Museum curators and biologial researchers recognized early on the importance of spatial elements. Although academic librarians are very familiar with cultural and historical collections, the specimen records in natural history museums often offer the only baseline data available on past environments. In the 1990s, a group of natural history museum experts created the Darwin Core metadata, comprised of 24 elements including the spatially related elements of country, state/province, county, locality, latitude, longitude, and bounding box.

Ecological Metadata Language was developed as a metadata scheme for exchanging information on ecological data sets. It is based on work done by the Ecological Society of America and the efforts of W.K. Michener and others who published the seminal article “Nongeospatial metadata for the ecological sciences,” Ecological Applications, 7(1): 330-342, 1997. Again, geographic coverage is given in bounding boxes.

This brief review of geographic elements in non-MARC metadata clearly indicates the disparity in approaches to geographic access.

Breaching Metadata Boundaries
Creating online digital collections brought into sharp focus the incompatibility of the place name world and the spatial world.

In 1997, an IMLS project entitled “Linking Florida’s Natural Heritage” explored the potential of using Z39.50 to simultaneously search museum specimen records and scientific literature. The geographic and taxonomic information of the Darwin Core metadata were identified as critical elements to tie records together. Standard MARC cataloging practices did not address either of these elements effectively. To ameliorate this deficit, a pseudo-MARC metadata was created for scientific literature that incorporated latitude/longitude coordinates in the 034 field to describe spatial coverage. The 752 field was used to represent the GNIS hierarchy of location: Country/State/County/Named Place. Part of the intent of the spatial enhancement was to create records that could function in a GIS mapping environment. This functionality cannot be fulfilled until a geographic search interface is programmed into the OPAC.⁸

In 1998, Tufts University began to build a temporal-spatial front end for its Perseus digital project. Although searching by latitude/longitude is not functional as of this writing, map visualizations are used extensively with the series of humanities texts and images that comprise the Perseus project.

Two existing digital projects do permit geographic searching using map interfaces and longitude/latitude searches. The Alexandria Digital Library provides access to 15,000 maps, images, and datasets. The Electronic Cultural Atlas Initiative of Berkeley uses the TimeMap project programs developed at the University of Sydney. This project allows the user to search for digital data on historical and archaeological resources by entering bounding box coordinates or by drawing a bounding box on a map. Of critical interest in this project is the metadata. It is enhanced Dublin Core where spatial coverage is defined by bounding boxes, e.g., dc.coverage.x.min -122.5184, dc.coverage.x.max -81.1516, dc.coverage.y.min 26.5847, dc.coverage.y.max 38.2987. This is the first enhancement of Dublin Core that facilitates spatial functionality.

Into The Future
Increasingly, digital initiatives benefit from integrating metadata from multiple disciplines. Without appropriate geographic elements, bibliographic metadata will remain isolated, accessible only through inexact textual searching. Spatial searching opens new investigative avenues in humanities as well as the social sciences and sciences. Linda Hill encapsulates the vision needed in libraries to successfully address a spatial future when she writes: “The metadata design challenge for non–GIS metadata is to incorporate a simplified representation of geospatial location that is consistent with the standards developed by the geospatial data community.” ⁹

Notes
1 Linda L. Hill and Greg Janee. “The Alexandria Digital Library Project: Metadata Development and Use,” in Metadata in Practice, editors Diane I. Hillmann and Elaine L. Westbrooks. Chicago: American Library Association, 2004, p. 118.

2 Gregory Crane. “Designing Documents to Enhance the Performance of Digital Libraries: Time, Space, People and a Digital Library on London,” D-Lib Magazine, v.6, no.7/8, July/August 2000, p. 1.

3 Distributed Geolibraries: Spatial Information Resources. A Summary of a Workshop Panel on Distributed Geolibraries [with members of the] Mapping Science Committee; Board on Earth Sciences and Resources; Commission on Geosciences, Environment, and Resources; and the National Research Council. Washington, D.C.: National Academy Press, 1999, p.1

4 Michael Buckland and Lewis Lancaster. “Combining Place, Time, and Topic: The Electronic Cultural Atlas Initiative,” D-Lib Magazine, v.10, no.5 May 2004, p. 4.

5 Hill, op.cit., p. 118.

6 Executive Order 12906 Coordinating Geographic Data Acquisition and Access: The National Spatial Data Infrastructure. Published in the April 13, 1994, edition of the Federal Register, Volume 59, Number 71, pp. 17671-17674. Amended by Executive Order 13286, published in the March 5, 2003, edition of the Federal Register, Volume 68, Number 43, pp. 10619-10633.

7 Wolfgang Kresse and Kian Fadaie. ISO Standards for Geographic Information. New York: Springer, 2004.

8 Fuller descriptions of this project are found in Priscilla Caplan and Stephanie Haas. “Metadata Rematrixed: merging museum and library boundaries,” Library Hi Tech, v. 22, no.3, Sept. 2004; and Stephanie Haas, Elaine Henjum, Mary Ann O’Daniel, and Joe Aufmuth. “DARWIN and MARC: A Voyage of Metadata Discovery,” Library Collections, Acquisitions, and Technical Services, v. 27, p. 291-304, 2004.)

9 Hill, op.cit., p. 128.