Wikipedia:Using maps and similar sources in Wikipedia articles
This is an essay. It contains the advice or opinions of one or more Wikipedia contributors. This page is not an encyclopedia article, nor is it one of Wikipedia's policies or guidelines, as it has not been thoroughly vetted by the community. Some essays represent widespread norms; others only represent minority viewpoints. |
This page in a nutshell:
|
Any map or line chart used in Wikipedia should conform with Wikipedia's policies of
- The presence of an object on a map is not sufficient by itself to show notability of a subject.
- Even maps produced using reliable sources (such as GISdata) can have minor errors as a result of errors in the underlying database, or the cartographer trying to overlay data from two non-linear sources. Minor map errors are common, for that reason any map detail that is key to the article should be confirmed with a separate map from a different publisher. Rarely are map errors notable, even if they have gone uncorrected for decades.
- Many cartographers intentionally introduce minor errors in inconspicuous locations as a form of copyright trap. Likewise, rarely are such introductions notable.
- Many companies publish a yearly edition of a map, and include the year as part of the title (e.g. 2009 Road Atlas). As these have to be drafted in advance, often the cartographer will draw projects under construction as completed, or proposed projects as under construction. This is an effort to increase the shelf life of the map, so as to not be obsolete before the year on the edition name has finished. (e.g. a highway expected to be completed by 2009 may be drawn as complete in the 2009 edition, even though it was still under construction when the map was drafted) This can introduce another source of error in an otherwise reliable map, should a project be cancelled or significantly changed. Such errors can be detected by comparing multiple editions of the same map.
- Any cultural bias apparent in a map should be clearly explained in a neutral fashion. For example, Wikipedia's article about the Falkland Islands sovereignty dispute features side-by-side maps showing the rival naming conventions used by Argentina and the United Kingdom for the named features of the islands, without implying one is correct. In cases where it is not practical or possible to show maps from each POV in a boundary or sovereignty dispute, a caption should explain which details of the map are disputed.
- Editors who use maps should be aware that maps covering large areas almost always have one type of distortion or another, depending on the map projection used. Care should be taken to select a map whose projection is appropriate for the purpose to which it is being put.
Illustration
When a map is used for illustration, the map should follow the same principles as photos used for illustration. Maps that are classed as primary sources may be used as illustrations provided that the accompanying text identifies their authorship.
Editor-created maps should be careful to only depict details supported by reliable sources in the article and common information that would appear on any published map relating to the subject. For user-created maps based on
Sources
Usage
Maps are used not only in
Remember that people who have good spacial visualisation ability have no problem using maps, but people who have poor spacial visualisation ability may find it difficult to relate to maps. This is often the underlying reason for disputes as to what constitutes original research and what does not.
From a mathematical point of view, line charts are nothing more than one-dimensional maps, so the same rules regarding the extraction of information apply.
Reliability
Similar to other types of sources, maps should not be
Relevance
Maps can be used to source specific details about the subject, consistent with the intended purpose of the map. For example, It would be appropriate to use a geographical map to source elevations, common names or relative locations, but not necessarily historical timelines. Maps depicting the historical growth of a city are appropriate for historical information, but may not be accurate in other details, such as geographical names. Road maps may be appropriate to source distances and routes, but not land ownership, etc.
Original research
Use of a map to source information beyond the intended use of a map can violate Wikipedia's policies, such as
When using maps as a source for topographic descriptions, care should be taken not to read more into the map than is already there. It is quite in order to state the “Valley X is ‘U’ shaped with
Description
Maps are often used to provide a description of linear features, such as a waterway, mountain range, road, railroad, or pipeline, etc., when doing so a single map should not be used the sole source used to provide the description. While a map is useful to source details in a general description section, other types of sources should also be used, if available. For some subjects the only sources available will be maps and it will be necessary to have the entire general description sourced from maps. Keep in mind that different types of information will be visible depending on the type of map used (i.e. road map, political map, topographical map, or recreational map). Ideally a map of each of those types should at least be consulted in drafting a description, if not used. For example if only a road map is used, the summary would consist almost exclusively of road features, and neglect geographical or political considerations. Using different maps of the same type (e.g. two road maps from different publishers) would likely not enhance the description, however may provide value to confirm a suspected map error or controversial detail. If a description only contains details from one map, the reader could save time by just looking at the map to get this information. The author should remember that a good article will describe an object above and beyond what is visible in a map.
See also
- Wikipedia:WikiProject Maps/Conventions, standard practices for displaying maps on Wikipedia
- Wikipedia:Manual of Style/Diagrams and maps, an inactive style guideline proposal