Professionally developed and freely accessible through the Internet, scientific data maps have great potential for teaching and learning with data in the science classroom. Solving problems or developing ideas while using data maps of Earth phenomena in the science classroom may help students to understand the nature and process of science. Little is known about how students perceive and interpret scientific data visualizations. This study was an in-depth exploration of descriptions and interpretations of topographic and bathymetric data maps made by a population of 107 non-science majors at an urban public college. Survey, interviews, and artifacts were analyzed within an epistemological framework for understanding data collected about the Earth, by examining representational strategies used to understand maps, and by examining student interpretations using Bloom's Taxonomy of Educational Objectives. The findings suggest that the majority of students interpret data maps by assuming iconicity that was not intended by the maps creator; that students do not appear to have a robust understanding of how data is collected about Earth phenomena; and that while most students are able to make some kinds of interpretations of the data maps, often their interpretations are not based upon the actual data the map is representing. This study provided baseline information of student understanding of data maps from which educators may design curriculum for teaching and learning about Earth phenomena. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]