rachelpasser:
mapsontheweb:
As someone who makes lots of thematic maps, it is clear to me that this map has some major issues, can you spot them before I tell you?
OK Rachel I give up…what’s wrong with it?
It lacks sufficient information! We have 2 options if we want to fix it:
This image is from colorbrewer2.org, a great resource for choosing your map colors!
If we changed the map to the green sequential color scheme outlined in the image above, the dark pink class would become that light off-white class, and the brightest green class on the map would have the darkest green color.
Just because a map repository tumblr reposts a map floating around reddit, does not mean the map was properly made.
Happy Mapping,
Rachel
Estimated average annual salary of teachers.
Let’s play…*What’s Wrong With This Map?
As someone who makes lots of thematic maps, it is clear to me that this map has some major issues, can you spot them before I tell you?
OK Rachel I give up…what’s wrong with it?
It lacks sufficient information! We have 2 options if we want to fix it:
- The key number we would need to know is the national average of estimated annual salary of teachers. Why is that? Because the mapmaker used a divergent color scheme. Divergent color schemes imply that the values being mapped diverge from the middle value. In other words, the white class above should include the states closest to the national average teacher salary. Look at the white class of states. Right now it just means states where the teacher salary ranges from $49,869 - $53,571. It would be more correct if the white class meant something like*“+/-$2,000 of the national average”. Subsequently, the light green and light pink classes ought to be something like*“+/- $10,000 of the national average”, and the brightest green and pink would be*“+/- $20,000 of the national average”.
Here is an example from on a previous post showing the proper use of a divergent color scheme. - If the mapmaker would rather map the current teacher salary quintile ranges shown on the map, then they would need to use a different color scheme. The best choice would be something sequential like the green color scheme outlined in the image below.*
If we changed the map to the green sequential color scheme outlined in the image above, the dark pink class would become that light off-white class, and the brightest green class on the map would have the darkest green color.
Just because a map repository tumblr reposts a map floating around reddit, does not mean the map was properly made.
Happy Mapping,
Rachel
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