Wikipedia:Using maps and analogous media: Difference between revisions

Revision as of 16:23, 8 May 2012

Revision as of 16:30, 8 May 2012

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===Original research===

[[File:1930 D&RGW WP.jpg|thumb|This map is a commercial map of the [[Denver and Rio Grande Western]] and [[Western Pacific Railroad]]s as they existed in 19301914. This map has been used appropriately in many wikipedia articles, both as a source and as illustration. The map is a valuable resource, showing the route and interconnection of the two railroads advertised, the route of their primary rivals, and several long abandoned and nearly forgotten [[short line railroad]]s and mining [[boomtown]]s in the [[western United States]]. However, the map's limitations should also be understood. It is a commercial map and is drawn on a slightly distorted scale, perhaps to minimize the fact the competing [[Overland Route (Union Pacific Railroad)|Overland Route]] is significantly shorter than the route of the railroads advertised.]]

Use of a map to source information beyond the intended use of a map can violate Wikipedia's policies, such as [[WP:OR|no original research]], [[WP:V|verifiability]] or [[WP:reliability|reliability]]. For example, if an object does not appear in the 1950 and earlier editions of a map, but does appear in the 1951 and later editions of a map, this does not prove the year of construction was 1950, unless there is additional information in the map, as this is using the map in a different manner from its intended purpose. It would be acceptable to say "The freeway first appeared on the department of transportation's map in 1951" in the above case. Some maps are totally unreliable if used in a manner for which they were not designed. For example, maps of mass transit systems are usually not drawn to a scale, as they are drawn to show the interconnections of a system in such a way that the map will fit in a limited space. This makes such maps unsuitable for other uses. For example, the [[Tube map|London Underground Map]] is an unreliable source for estimating the distance between two stops, but it is an excellent source for the number of stops on a given route.