Showing papers on "Choropleth map published in 1993"
TL;DR: This model goes beyond simple cluster or centroid analysis by employing specific serial murder research, overlapping modified Pareto functions, and Manhattan distances to generate a choropleth probability map that indicates the areas most likely to be associated to the offender.
Abstract: Clues derived from the locations connected to violent repeat criminal offenders, such as serial murderers, rapists, and arsonists, can be of significant assistance to law enforcement. Such information allows police departments to focus their activities, geographically prioritize suspects, and to concentrate saturation or directed patrolling efforts in those zones where the criminal predator is most likely to be active. By examining spatial data connected to a series of crime sites, this methodological model generates a choropleth probability map that indicates the areas most likely to be associated to the offender—home, work site, or travel routes. Based on the Brantingham theoretical structure and the routine activities approach, the model goes beyond simple cluster or centroid analysis by employing specific serial murder research, overlapping modified Pareto functions, and Manhattan distances. The methodology is also sensitive to the target/victim opportunity backcloth, landscape issues, and problems of spatial “outliers.”
48 citations
1 Jan 1993
TL;DR: A set of presumably effective procedures common to experienced choropleth map users were ascertained and, using these procedures and others developed in a prior study, and their knowledge as cartographers, the authors developed a set of Presumably effective procedures.
Abstract: Today's computer graphics technology enables map users to acquire spatial knowledge in ways not possible with traditional static displays; for example, classes of data on a choropleth map can be sequenced from low to high values. Although sequencing and related approaches are often judged to be novel and exciting, it is unknown whether such approaches enhance or diminish knowledge acquisition. In a broader vein, we might ask what is the optimal technique for acquiring knowledge from a choropleth map? The optimal technique might involve a novel display approach, or modifying a method for learning a traditional static display. In this vein, two experiments were conducted. In the first, learning procedures common to experienced choropleth map users were ascertained. Using these procedures and others developed in a prior study, and their knowledge as cartographers, the authors developed a set of presumably effective procedures. In the second experiment, three choropleth display approaches were compared for th...
28 citations
1 Jan 1993
TL;DR: In this paper, the interaction between color and visual processes people use to search choropleth maps was examined, and two experiments were performed in which subjects searched hymnal maps.
Abstract: The purpose of this research was to examine the interaction between color and the visual processes people use to search choropleth maps. Two experiments were performed in which subjects searched hy...
12 citations
TL;DR: Choropleth mapping as mentioned in this paper is one useful cartographic technique that takes geographic instruction beyond the limits of most secondary geography textbooks, and it offers the possibility of extending the level of geographic thinking from the description of factual information to interpretation of comparative information and inferences.
Abstract: Choropleth mapping is one useful cartographic technique that takes geographic instruction beyond the limits of most secondary geography textbooks. It is a simple technique to teach, and it offers the possibility of extending the level of geographic thinking from the description of factual information to interpretation of comparative information and inferences. Choropleth maps of socio economic characteristics for Middle America, for example, raise important questions about Middle American welfare, culture, democracy, and U.S. foreign policies which might otherwise not be discovered or considered by students.
4 citations
TL;DR: In this paper, the authors present an atlas review of choropleth maps that appear in a selected geographic journal for a specific time period and provide an opportunity for the student to judge the published maps against accepted cartographic standards.
Abstract: The purpose of this exercise is to help students review some important aspects of choropleth maps that appear in a selected geographic journal for a specific time period. Through this exercise, students in a cartography course can identify the most common number of classes used for choropleth maps, the most popular method used to determine the class intervals, the most frequently used legend structure, and the most popular symbol used in choropleth maps. This exercise will provide an opportunity for the student to judge the published maps against accepted cartographic standards. The exercise can be used either as an alternative to or independently of the atlas review.
3 citations
TL;DR: This article found that monochrome classed choropleth maps were found to minimize dispersion, compared to a two opposing colours scheme, a dot density map, a pie map, and a categorical (hue-based) colour scheme.
Abstract: SUMMARY Two experiments observed performance on a cluster identification task across a variety of common statistical maps. Stimulus maps displayed mortality rates for several diseases and subjects had to identify regions of the map that were perceived to form a cluster of particularly high (or low) mortality. Subjects marked the perceived centroid of each cluster, and analyses focused on the dispersion of centroid location across subjects. Under these circumstances, monochrome classed choropleth maps were found to minimize dispersion, compared to a two opposing colours scheme, a dot density map, a pie map, and a categorical (hue-based) colour scheme. Maps using a famiUar geographical unit (i.e. a U.S. state) supported better recall of the information than maps using less familiar and smaller geographical units. The results were found to be interpretable within current cognitive theory.