How Maps Work

Online Maps

Maps intended for online viewing also have different requirements than those meant to be viewed on paper. Turner explains:

If you're developing a map specifically for the Internet, generally the fonts have to be larger so you can read the type on screen. You have fewer choices in color because not every color will necessarily output correctly if somebody's trying to print that map. So, because of limitations in color, because of the limitations in type size, compared to a print map it generally has to be much simpler…You generally develop a map that's going to fit on a standard computer screen so that the user doesn't have to pan around to be able to interpret the information.

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With all of this in mind, the cartographer has to gather data and figure out how to use visual elements to present it on the map. This requires more than just accurately outlining continents and bodies of water. The cartographer has to use colors, lines, symbols and text to make sure that the reader can interpret the map correctly. These visual elements help make it clear which parts of the map are most important, as well as which parts are in the foreground and which are in the background. Often, the cartographer can use a GIS to examine multiple versions of the same map to determine which one will work best.

Even with the help of a GIS, successfully creating a map requires a cartographer to have a lot of specialized knowledge. Many cartographers have degrees in cartography or in related subjects, such as geography, surveying or mathematics. Because of the increasing prevalence and complexity of geographic information systems, cartographers also need to be skilled at using computers. In addition, many cartographers are also interested in fields that make use of lots of maps. Turner says, "For me, it's weather and politics. For others it might be languages; for others it might be geology. For some it might be history, whether American history or world history."

Improvements in cartographic techniques and in geographical information systems have made it possible for people to get very specialized maps very quickly. This is a big improvement that has taken place over the last thirty years. Previously, getting a high-quality, specialized map could be challenging, especially on short notice. The next challenge is to get new maps into public view faster. "Typically," says Turner, "the lag time between when a map is developed and when it is available to the public in print or on the Web is three to six months, and that is I think an area that people are going to expect improvement in."

Fortunately, much of the technology required to gather data and quickly convert it into a map already exists. In the future, people may be able to access and download new, updated maps in real time. This could also affect the accuracy of online directions and turn-by-turn GPS systems.

To learn more about maps, cartography, geography and related subjects, check out the Lots More Information page. See more pictures of maps on the next page.­