Abstract Communicating with value-by-area cartograms is at best a difficult task. However, the mapmaker can render a cartogram more meaningful in communication by retaining the basic shapes of the statistical units. This idea was examined and several tests were administered to subjects to gain information about points along state shapes that are used as cues in map reading. It was determined that map readers mentally generalize geographic shapes into ones that are similar to the over-all shape quality of the originals. In cartogram construction, the mapmaker should provide at least those points along state outlines that are proven to be the cues for shape identification. Anything less will detract from its ability to communicate effectively and, in fact, if this is the case alternate mapping methods should be employed.
Thematic mapping essentials techniques of quantitative thematic mapping designing thematic maps electronic map production effective graphing for cartographers and appendices.
ABSTRACT Total map perception integrates geographic material (the base map) and thematic material (the distribution which is mapped). Psychological studies of the figure-ground relationship indicate that maps should be designed so that thematic symbols are experienced as figures, and base map materials as ground. Figure perception is enhanced by heterogeneity, contour, and area or enclosedness; the cartographic designer has greatest control over heterogeneity. Tests of preprinted area patterns for heterogeneity indicate that the perception of figures against ground is most enhanced, other things being equal, by patterns which have coarser texture and a higher percentage of area inked.
Abstract The value-by-area cartogram is a form of mapping often used for its visual impact. The average reaction to cartogram area is potentially error free in that the components of a typical value-by-area cartogram are areal shapes. When not in map form, map readers generally respond to these areas in a linear fashion. Results of a testing program to measure this ability suggest that the accuracy of the average response depends upon whether shapes are amorphous or square and whether the anchor stimulus is relatively large or small. The accuracy of responses to the cartogram compare favorably with responses to a five-class Flannery circle map. Map reader attitudes point out that these cartograms are thought to be confusing and difficult to read. At the same time they appear interesting, generalized, innovative, unusual, and having—as opposed to lacking—style. Communication depends on how well the cartographer has maintained the overall shape quality of the original geographical units and the provision of an adequate stimulus anchor, a geographical-base inset map, and labeling on the statistical units.
List of Figures and Tables Contributors Preface Acknowledgments Cartography in the Atlas of Crime by Elaine Hallisey Hendrix Geographic History of Crime Brief History of Crime Mapping by Borden D. Dent of Personal Violence Homicide by Keith Harries Assault by Jose Javier Lopez Rape in the United States by Kathleen C. Basile Robbery by Doug Williamson Against Property Burglary by Susan M. Walcott Auto Theft and Detecting Chop Shop Locations by Nancy G. La Vigne, Jill Kathleen Fleury, and Joseph Szakas Environmental Crime by Nancy L. Winter and Ute J. Dymon Confronting Computer by John Jarvis and Gordon R. Wynn Family Violence Intimate Violence by Denise A. Donnelly The Spatial Dimensions of Child Abuse and Neglect by Linda S. Turnbull Elder Abuse by Denise A. Donnelly Animal Cruelty: A Spatial Investigation by Linda S. Turnbull Organized and Entrepreneurial Mapping the Set Space of Urban Street Gangs by George E. Tita The Spatial Dynamics of Drug Trafficking by Linda S. Turnbull Prostitution by Jacqueline Boles Modern Maritime Piracy by George J. Demko Film at 11 Crimes Serial Murder in the United States, 1860-1995 by Christopher G. Missen Domestic Terrorism by Damon D. Camp Hate by Damon D. Camp School Violence by Pamela Riley and Joanne McDaniel Mental Mapping Criminals' Mental Maps by David Canter and Samantha Hodge Cognitive Maps and the Fear of Crime by Patricia Gilmartin Maps in Detective Fiction by Leslie Edwards Criminal Justice A Spatial Analysis of American Police Killed in the Line of Duty by Robert J. Kaminski, Eric S. Jefferis, and Chanchalat Chanhatasilpa The Concept of Community Policing and a Case Study of Lima, Ohio by William V. Ackerman Crime Scene Sketch by W. Jerry Chisum Police Department Use of Geographic Information Systems for Crime Analysis by Elaine Hallisey Henrix Capital Punishment by Keith Harries Index
MAPPING REGIONAL SHOPPING CENTER TRADE VOLUMES IN ATLANTA, GEORGIA Borden D. D en t* INTRODUCTION. The purpose of this paper is to report on a study that was conducted in Atlanta, Georgia, to determine the retail trade areas of eight large regional shopping centers distributed throughout the metropolitan area. A regional shopping center is defined as any planned center with at least one large department store. The present study focuses on the application of a method not frequently seen. An adaptation of the Huff model was devised, applied to the study area centers, and used to determine if the adaptations give reasonably reliable results in delimit ing retail trade areas in practical application, especially when compared to the familiar shopper survey technique. The study is not theoretical in its orientation; it was planned to develop a simple, yet firm, base upon which quick reliable estimates could be made regarding components of the retail landscape of any large metropolitan area. BACKGROUND NOTES. Geographers and others interested in the spatial aspects of marketing have carefully studied many of the char acteristics of retailing at the urban scale, especially with regard to trade area delimitation. One of the earliest certainly was William J. Reilly, who formulated what is now generally known as “Reilly’s Law of Retail Gravitation.” (1) Subsequently, others joined this vigorous research, notably Converse, who devised slightly altered versions of Reilly’s original formulations. These have been called the “New Laws of Retail Gravitation.” (2) Central place theory is implicit in Reilly’s research although it was done prior to Christaller’s Die zentralen orte in Siiddentochland . Fundamentally, these laws are not theoretically based, but are rigid, deterministic devices that allow researchers 1) to ascertain the relative strengths of two towns’ retailing activities, and by extension, 2) to determine breaking points which give approximations for develop ing trade areas around centrally located towns. The mathematical formu lations for these laws can be found elsewhere. (3) There have been fewer studies on retail trade area delimitation at the intra-city level. Yet from these it is clear that trade area delimitation at this scale is exceedingly difficult. The principal reason is that as shoppers have so many intervening opportunities, it becomes more burdensome to place them in one, well-defined trade area. (4) Most of •Dr. Dent is associate professor of geography at Georgia State University. The paper was accepted for publication in June 1972. 70 S o u t h e a s t e r n G e o g r a p h e r the research and practical application has been to develop trade areas around individual selling units, the chain-store supermarket for ex ample. (5) A few studies have dealt with intra-city trade areas of large shop ping centers, perhaps most recently by Brunner and Mason. (6) These researchers have found that in addition to the recognized factors of population, population density, purchasing power, and others, driving time is also a factor in consumer shopping center preferences. (7) Spe cifically, their findings for Toledo, Ohio, led them to conclude that the 15-minute driving time line was adequate for delimiting a center’s principal trade area (three-quarters of the center’s patrons resided within this area). Subsequent research by Cox and Cooke has supported the findings, but also points out that shopping center size and natural barriers around each center also influence trade area. (8) HufFs work is notable in this discussion because it was the basis around which the present research was formulated. Huff has stated that for intra-city trade area delimitation, Reilly’s law of retail gravitation fails because 1) it leads to a “fixed boundary” for trade areas, 2) there is no good reason to assume that a constant exponent in the equation would exist to describe all intra-urban consumer movement, 3) it incor porates little theoretical framework. (9) As a consequence of these stated limitations, he developed a more behaviorally oriented model, with the consumer at its center, to assist in developing shopping center trade areas. Huff states: “The analysis will utilize the conceptual prop erties of the gravity model, but its focus will be on the...
The map projection is considered an important variable among map design elements. In some instances cartographers need to consider projections on which continental shapes are closely preserved. The proposition offered here is that continental shapes are best preserved on the familiar orthographic projection. A world projection is devised by developing a composite of several orthographic views, each of which best illustrates the five major continents. Subjects were tested for judgments of continental centres, and these are used for orienting the oblique projections. The final composite world projection is new. This process demonstrates how the map projection and its selection is a dynamic part of overall map design.
"Map Commentary" is a new section being initiated with this issue of The American Cartographer. As readers and cartographic editors are well aware, there are many aspects of cartography that are not easily incorporated into full-length articles nor do they fall into other categories of items currently included in the journal. This new section is intended to fill a part of that gap. It will be devoted to the discussion, critical as well as complimentary, of selected map examples. In this issue we have a commentary on the design of a map, but interpretive and other essays centered on specific maps will also be welcome as potential contributions for this section.
