The document is designed to help map readers comprehend the uses and limitations of maps. Intended predominantly for college students of geography, graphic arts, and public communication, the resource paper should also be of general interest to informed citizens and map enthusiasts. The document is presented in six chapters. Chapter I discusses and defines major elements common to all maps--projection, scale and generalization, and symbolization. Chapter II addresses the process of cartographic communication and identifies factors which influence the successful transfer of a map's message from author to reader. Factors include the cartographer's data, intent, design, and reproduction process, and the reader's understanding, intelligence, biases, and perceptions. Chapter III explores the relationship between map projections and effective communication and describes methods for constructing three nontraditional projections. Chapter IV examines methods for reducing complexity of mapped patterns. Topics discussed include choroplethic maps, classification errors, pattern and perception, cartographic correlation, and information overkill. Chapter V shows how map distortion can serve a variety of goals, such as route planning, data processing, advertising, advocacy, and research. The final chapter presents concluding remarks. A major conclusion is that both map reader and map author should strive to understand the process of cartographic communication. (Author/DB)