Maps as Representations: Expert Novice Comparison of Projection Understanding

Part of being able to reason geographically means having a deep understanding of maps as specific, albeit limited, representations of the surface of the earth. In this investigation, we examine how varying levels of geographic expertise facilitate reasoning with maps as representations of the earth's surface. A total of 30 participants (tenured geography professors, undergraduate geography majors, geography undergraduates currently enrolled in their first cartography class, and preservice teachers) were asked to draw a series of lines indicating the shortest actual distance between 2 locations, as they would be on the earth's surface. Participants completed these tasks among 3 pairs of locations on a map of the world and 2 pairs of locations on a map of North and South America. As expected, geography experts performed significantly better than novices and preservice teachers on both maps. More important, however, is that experts' performance can be differentiated by the reasoning in which they engaged. Experts often knew the solution immediately, knew the rules for generating a solution, or had enough knowledge and experience to generate the correct cognitive rules. In contrast, novices and preservice teachers could not solve the problems directly, knew fewer rules, and could not generate useful rules for solving the problem. Of particular interest across all groups of participants was the use of a visualization strategy to solve these tasks. We conclude by discussing the implications of this study for understanding geographic expertise and improving classroom map instruction both for K-12 students and for preservice teachers.