The project described in this article enables users to create and customize electronic thematic maps through the Internet. The Pennsylvania County Mapper (http:// www.maproom.psu.edu/mapper/cbp) provides economic and social data, by county. This prototype targets users who may not have access to electronic mapping programs and those with few mapping skills or only moderate computer skill.
In January 1997, the Pennsylvania State University Libraries Map Section launched a new World Wide Web site. With the Pennsylvania County Mapper (PA Mapper), users create maps employing data from the County Business Patterns (CBP) series from the U.S. Bureau of the Census. Users select from the list of data classifications, choose a statistical interval and color, then map or graph the data, resulting in a custom map.
Although several sites provide interactive mapping on the Web, including MapQuest from GeoSystems (http://www.mapquest.com) and the Tiger Map Server from the Bureau of the Census (http://tiger.census.gov), few offer the ability to create thematic maps, interactively and with the amount of flexibility provided here.(1) With the PA Mapper, users select the data, control a number of display features, and quickly create a map designed along accepted cartographic principles. The enthusiastic response to the PA Mapper has given us the impetus to add more data, more geographies, and additional mapping options. This article describes the conditions leading to development of the site, the basic requirements for service, and relates our experiences with building an online mapping system.
Almost everyone with access to a computer has seen some form of electronic mapping program or heard about geographic information systems (GIS). The demand for these services in libraries has steadily increased. In response to this demand, and to organize the growing amount of electronic data, some university and public libraries now provide access to GIS or electronic mapping.(2) These programs, however, are often expensive and intimidating to novice users. The expense, the software learning curve, and a lack of map skills limit the number of librarians, patrons and home computer users able to effectively apply and benefit from electronic mapping services.
In many university and public libraries, GIS specialists constitute a small user group. They almost always approach the library for data, not for software and hardware facilities. They have access to GIS labs and have developed the skills necessary to analyze and map the data. In contrast, a much larger group of users consists of undergraduates and researchers in disciplines that do not traditionally use GIS, such as history and education. These users often have genuine mapping applications, but require access to hardware and software, instruction on both from the library staff, and also assistance in handling and subsetting large data sets.
At the same time, more users are logging onto the Internet from homes and offices. Most users search the Internet expecting that data and information will be readily available (beyond bibliographies and advertisements). A number of library and government sites supply data directly online, including the University of Virginia's library (http://www.lib.virginia.edu/socsci/) and the Consortium for International Earth Science Information (http://www.ciesin.org). In addition, sites such as the Perry-Castaneda library (http://www.lib.utexas.edu/ Libs/PCL/map_collection) and the University of Georgia (http://www.libs.uga.edu/darchive/hargrett/maps/ maps.html) provide static map images through the Web. Thus, users expect data and maps to be delivered through the Internet.
The exponential growth of the Internet and the great numbers of data sets flooding into libraries have increased the stress on staff who must provide instruction and support to both on-site and …