Topic on Talk:Wikimedia Maps/2015-2017/Conversation about interactive map use

Nilfanion (talkcontribs)

OSM uses Web Mercator projection, which is fine for most uses. As long as it correctly interacts with location markers its probably better than the equirectangular projections typically used by existing location maps.

However, other projections are far better for specific uses. The polar regions need a different projection, and are the most extreme case. The current preferred projection for global maps is the Robinson projection, and maps at the continental and national scale benefit from alternative projections.

Personally, I'd prefer a static map on a good projection to an interactive one on a poor one.

CKoerner (WMF) (talkcontribs)

This sounds to me like a great example where a static map, in the proper projection for the intended use, would be preferable over an interactive map using Web Mercator. I'll add it to the list of Pros and Cons.

Nilfanion (talkcontribs)

Agreed - but it would be good in future to allow other projections. An article like Terra Nova Expedition could really benefit from an interactive map.

Sabas88 (talkcontribs)
Yurik (talkcontribs)

@Nilfanion:, @Sabas88:, @TheDJ: @Jheald: you might like this demo -- hopefully will be available soon in production as well. All fully dynamic, from OSM database and Wikidata, using graph extension. Try to hover over the state capitals. And yes, the map of USA uses a different projection.

Nilfanion (talkcontribs)

Looks like a decent start. :)

However, the Indonesia and UK maps are particularly poor because the OSM areas do not reflect the coast. The shapes really need to be clipped to the coastline (ideally high water) before being displayed. Major lakes such as the Great Lakes should also be visible.

This reflects one area where OSM data is currently low quality - offshore boundaries. Ideally the maritime boundary should reflect something meaningful, like claimed territorial waters or the EEZ, but they look like more a crude approximation of a 12-mile limit. IMO better not to display this at all than show it as on the Netherlands map.

A stylistic concern - it would be useful to have option to display non-subject areas (such as Canada on the US map). It can be useful to clearly show the relationship to surrounding areas in certain contexts, while on other maps its irrelevant. That is a binary choice, which depends on the intended use of the map.

Also another concern that you may not have considered - POV. Argentina is a good case in point - what about the Falklands, or Antarctica?

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