The MARC bibliographic record is an industry-wide standard for cataloging bibliographic information, used extensively by libraries, database vendors, and library services companies across the United States. The MARC record contains descriptive information of an item including author(s), titles and variants of titles, subject headings, a classification (or call) number, as well as other bibliographic data elements based upon the format of the item (Furrie, 2000).
Recently, the academic library community has begun to address how to describe digital geospatial information using the MARC format (Welch & Williams, 1999). In 1998, several offices of the Library of Congress (the Cataloging Policy and Support Office, Network Development and MARC Standards Office, and the Geography and Map Division) issued standards for identifying materials to be catalogued as a map format and as a computer (formerly machine-readable data file) format (Larsgaard, 1999). More recently, the Joint Steering Committee for the Revision of the AACR2 (Anglo-American Cataloging Rules 2nd edition) discussed changes in the rules. Chapter 3 of the AACR2r deals with the graphic representation of information concerning digital cartographic materials. Chapter 9 outlines the description of computer files and data, though the focus of the chapter appears to be on numeric databases rather than geospatial data. By interpreting information about the spatial data provided by the producer of the geospatial dataset, a cataloger can create a more detailed bibliographic description (Larsgaard, 1999).
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In describing the primary nature of an item, especially its intellectual and physical form, Larsgaard (1999) offers several MARC examples for geospatial data on CD-ROM. For example, if the 007 field, which describes most cartographic materials, is used to describe an electronic atlas, it would display as:
007 |a a{GMD: map} |b d {SMD; atlas} |c {do not use this subfield} |d c{multicolor}
|e e {physical medium: synthetic} |f n {type of reproduction:not applicable} |g z {production/reproduction details: other} |h n {positive/negative aspect:not applicable}
(Larsgaard, 1999, p. 366).
After the 007 field, the 008 field is intended for coding primary characteristics of the material. Values for the 008 field are often given in the mnemonic beginning line of a record. Larsgaard (1999) notes that each 008 field begins with the same 00-17 positions and ends with the same 35-39 positions. These positions have to do with dates (Date), language (Lang), when the record was modified (Mrec), and cataloging source (Srce). The remaining fields are Relief, Projection, Type of cartographic material, Government publication, Index, and Special format charac- teristics (Larsgaard, 1999, p. 367).
In the 245 field (General Material Designation), the Anglo-American Catalog- ing Committee for Cartographic Materials is considering using the term electronic resource in the 245 field, as a substitute for computer file, to better reflect digital geospatial data. For example, 245 |h {cartographic material {electronic resource}}
(Larsgaard, 1999, p. 367).
Welch and Williams (1999) also note several concerns with cataloging digital data within the Mathematical Data Area, including the 256 field on file character- istics, the 352 field on digital graphic representation, and the 342 and 343 fields on geospatial reference data area. For example, classifying scale for geospatial objects is difficult. Since the user can zoom in and out of different scales within a GIS interface, the phrase “scale not given” is used for descriptive purposes. Another aspect of scale is that of the input scale. When a digital cartographic item has been digitized from a paper map, certain elements are included in the electronic version selected on basis of scale. The input scale would then affect both the content of the item and the extent to which the data can be used for other purposes.
Used in recording projection, the 342 field uses additional subfields to add information on the longitude of central meridians and latitude of projection centers.
In effect, the 342 field records information about the vertical and horizontal coordinate systems of a data set (projection or grid) and may be repeated (Welch
& Williams, 1999). The 255 field also contains the geographic extent (coordi- nates) of the geospatial dataset in a subfield of c.
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The information described above is derived from the metadata description when the metadata producer has followed FGDC standards. Describing digital geospatial data can be difficult because it utilizes a specialized nomenclature that is often unfamiliar to non-map catalogers. The availability and comprehensiveness of metadata and local library cataloging policies determine the amount of information entered in the Digital Graphic Representation Fields (352) and Geospatial Refer- ence Data fields (342 and 343) (Welch & Williams, 1999; Larsgaard, 1999). For example, the standard adopted by the USF GIS Research and Data Center includes basic descriptive bibliographic and cartographic elements of the GIS item, including data source, title, spatial display characteristics, and software require- ments for viewing. The 352 and 342 fields are used when a need arises for records that are more comprehensive.
When the cataloger cannot adequately describe the geospatial data using the mathematical data fields, additional information can be included in the MARC note fields. The 514 field (data quality note) contains information about the accuracy and completeness of the data. The 551 field (entity attribute) allows the cataloger to add attribute information to the record. The 538 field (systems requirements) would include notes on the type of GIS software processing abilities needed to properly display the digital spatial data. (Welch & Williams, 1999).
When classifying geospatial data (050 field), the Library of Congress treats digital cartographic material as a form subdivision in its G classification schedule.
The cataloger classifies geospatial data by map or atlas number without regard to style, and uses a format indicator to indicate the location of the CD-ROM or diskette. When creating subject headings for this data, the Library of Congress uses the 653 field form, which allows the construction of an index term added entry that is not constructed by standard subject heading/thesaurus-building conventions (e.g., Maps—Digital—Raster or Maps—Digital—Vector). Use of this form division can also be used after other materials designations such as Remote-Sensed Images-Digital-Raster (Welch & Williams, 1999; Larsgaard, 1999).
The amount of bibliographic information for geospatial data can become quite lengthy. If there is good metadata and original documentation available, the cataloger can create detailed MARC records for the data. Another strategy to enable access to information is to mount the geospatial metadata on a separate webpage, and then supply the URL for the user through the MARC record via either the 500 field (general note) or the preferred 856 field (electronic location and access) (Welch & Williams, 1999).
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