Although it is necessary to understand map projection to read a map of the world and view the world (surface of the Earth) accurately, geography teachers tend to avoid teaching map projection because they think it is both difficult to understand and to teach. Information technology provides more effective and attractive teaching methods and materials. Shadow images of the globe created by a light source are often used to explain map projection, but this method is not so effective. Transforming globe gores (polyconic projection gores) into various projections is better way to illustrate map projection. Computer software can be used to draw maps of the world using various projections, and to make digital images that illustrate map projections and the order of projections for teaching purposes. They can then be published as educational materials on the Internet. Web pages are constructed to teach the distortion inherent in a Mercator projection map with Google Maps API and Google Earth API. One of these Web pages shows users the great circle line and the rhumb line between any two points on Google Maps (Mercator projection) and Google Earth (digital globe). Another shows users equidistant circles and cardinal and inter-cardinal directions from any point on Google Maps and Google Earth. Teachers and students located anywhere can access the Web pages and study using these on-line materials.
