Visualization of Spatial Relationships in Mobility Research: A Primer

• NCJ Number: 214255
• Author(s): Elizabeth R. Groff; Thomas McEwen
• Date Published: March 2006
• Length: 65 pages
• Grant Number(s): 2003-IJ-CX-0150
• Agencies: NIJ-Sponsored
• Publication Type: Issue Overview
• Award: Mapping and Analysis for Public Safety: Funding for Spatial Data Analysis

Annotation

This report provides an introduction to visualizing flows and spatial relationships among offender, victim, and crime locations, and the cartographic techniques that could be applied to mobility triangle data.

Abstract

The mapping of crime has been done for hundreds of years. More recently, some researchers have become interested in developing spatial typologies of crimes that incorporate the relationship between offender and victim residence and the location of the crime, specifically mobility triangles. Mobility triangles are formed from three locations: offender home address, victim home address, and site of the crime. The relative spatial relationships among the three locations constitute the basis of the typology. However, little explicit attention has been given in the criminological literature to the various methods available for visualizing the information contained in spatial typologies such as mobility triangles. This report supported by the U.S. Department of Justice, National Institute of Justice attempts to fill that gap by focusing on cartographic techniques available to visualize the movement of offenders and victims among neighborhoods and depict the relative relationships among locations that are captured in mobility triangle data. After reading this report, one should know what types of mapping techniques are available and when each is appropriate for a particular analysis, be familiar with how to symbolize specific map types, be able to articulate the types of questions that can be answered using each type of map, be familiar with different types of software available to construct flow maps and their relative advantages and disadvantages, and know how to symbolize the relationships revealed by mobility triangle classification. The first section of the report explains the data used and sets out the framework for organizing the various cartographic techniques available. This is followed by demonstrating the types of questions that can be answered through the examination of mobility data at a variety of scales. Exhibits, references and appendixes 1-3