Sunday, February 3, 2008

Maps - 3

Directions are simpler and very specific. They concern how to get from a point of origin to another point of destination. If followed precisely (assuming they are correct) they will allow you to get to where you are heading. But to keep them simple they may omit helpful landmarks that allow you to find your way. The reason we suggested that you focus on a driving trip was to encourage you to consider the possibility that you could drive past a turnoff specified in the directions. Directions are less useful if you make a mistake and get lost as a consequence.

Maps are different in this respect and hence useful to have even if you also have directions. Since maps contain many locations and many routes all in a single view, with the aid of a map it is possible to re-orient yourself after you have missed your turnoff and having done so to find a way to get back on the correct path. You can construct directions from maps and do this for many pairs of origin and destination points. Maps are more complex than directions but also more general.

There is power in this generality. It means you need have only one map to handle many different routes. That map can help you frame location information, even for items that don't appear on the map. Those items are situated between roads or other markers that do appear. There is also another important generality about maps that applies in a different way. Reading a road map is a skill that takes time to acquire but once you've learned to read one road map you should be able to read any road map. So the skill of reading a map is broadly applicable. Maps are designed to conform with certain standards to make them generally readable.

While maps are generalizable abstractions of reality they also distort reality in certain ways in that in actuality things appear other than they appear on the map. Can you give some examples of how maps distort and in addition for each example provide an explanation why the distortion occurs?

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