Geographic Information Systems: A Guide to cessing, spreadsheets, and data base the Technology was born of need-the need management. Recently, geographic infor­ for a comprehensive work on the emerg­ mation management technology came to ing field of geographic information man­ the desktop, signaling a new era of in­ agement technology. creasing use and popularity. Enthusiastic We encountered the need often in our users have long been the main source of work at PlanGraphics, Inc. , a leading com­ grassroots support and growth. We perceive at least three broad audi­ puter consulting firm that specializes in ences for this book: 1) executives, man­ the design and implementation of geo­ agers, professionals, and other lay people; graphic information systems (GIS) and as­ 2) practitioners and technicians; and 3) stu­ sists organizations in using the technology to solve problems and perform work more dents and academicians. We recognize efficiently. We needed it, our clients that GeographicInformation Systems cannot needed it, and it didn't exist. completely satisfy the disparate needs of Geographic information management any of these groups, but we have tried to give each of these audiences a foundation technology-using computers to map, draw, store, and manipulate spatial data­ upon which to build. Our purpose is two­ fold. We hope to aid those considering, evolved independently in many places with many variations.