ASSESSING THE EFFECTIVENESS OF DIFFERENT 3-D MAP STYLES

Anaglyph maps are increasingly being incorporated into introductory geology courses as a means to convey landscapes in stereo as three-dimensional surfaces. Although these maps do appear to engage students more effectively than traditional topographic maps, there has been limited research to quantitatively measure differences in the effectiveness of different anaglyph map styles. In particular, we were interested in evaluating the relative effectiveness of stereo contour maps and gray-scale shaded relief maps that lack contour lines.

During previous studies, we found that students harbor a surprising number of misconceptions concerning water flow across a land surface. Some of these, like the tendency to believe water in the northern hemisphere always flows to the south, were expected. Others were unexpected, such as a surprisingly large number of students who believe that water flows parallel to contour lines rather than cross them. This misconception even occurs when students are viewing maps in stereo as three-dimensional surfaces. In many cases, contour lines appear to confuse students more than they help students visualize the land surface.

To evaluate this idea, students were asked to draw the path of water flow on two types of stereo anaglyph maps: anaglyph maps made with contour lines and gray scale anaglyph maps that lacked contour lines. The study results confirm that contour lines can adversely affect students' perception of water flow, but also show that gray scale maps are not a perfect panacea. Gray scale maps foster their own set of misconceptions about water flow so instructors need to be aware of the misconceptions inherent to each map style. The results of the study are not limited to misconceptions about water flow, but provide rich insights into how students use maps to visualize land surfaces.