# Choropleth Maps

Unlike the previously discussed maps, which did not use predefined regions (states, countries etc), choropleth maps use the shapes of the regions.

![](https://192301203-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M5-0RG_uqhxyMNjpMUW%2F-M5-0SvQ45Rarxg8L2lA%2F-M5-0WB5YtI9xf5GOj7x%2Fchoropleth.png?generation=1586990829493426\&alt=media)

These maps are very popular and they are easy to use and interpret. However, they can be easily misused, resulting in misinterpretation and deceit.

* We must be very careful in choosing the level of detail for the regions (i.e. countries/states/counties/regions...)
* We must also use color maps carefully
* Choropleth maps, when used to depict categorical information, cannot be used to depict quantities (they can only use one channel at a time)

  ![](https://192301203-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M5-0RG_uqhxyMNjpMUW%2F-M5-0SvQ45Rarxg8L2lA%2F-M5-0WBHCFLI_80IdQYT%2Fchoropleth_votes.png?generation=1586990829335405\&alt=media)

  For example, in the map above, we can only visualize red/blue i.e. which party received majority votes in a region, but cannot visualize the number of votes per region. This gives a very partial view of the data.