Knowledge Acquisition from Choropleth Maps

Abstract

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 their effect on knowledge acquisition: (1) a static map in which no procedures were taught (control group); (2) a static map in which effective procedures were taught (effective procedures group); and (3) a sequenced map in which the nature of sequencing was determined, in part, by effective procedures (sequenced group). The results revealed no significant difference among the three groups in terms of speed or accuracy, but the effective procedures group responded fastest on all questions, and the control group performed faster than the sequenced group on 70% of the questions. Keywords: KNOWLEDGE ACQUISITIONCHOROPLETH MAPSSEQUENCING