Module 7 - Choropleth Maps

This week was a seemingly innocent little lab assignment designing a few choropleth maps. It turned out to require quite a bit of experimenting - with data values, data representation, and overall map layout. Choropleth maps are common and familiar to almost all of us. If you've ever looked at the maps in a National Geographic article or watched an election race on TV, you've probably encountered one of these maps. They are used to show aggregated data whose spatial patterns fall within enumeration units or boundaries. In our case, demographic data about Europe, which we used to create three data frames in one map, including population density and female/male population percentages per country. We also read up on proportional and graduated symbol mapping and added wine consumption data to our population density map.

The first tricky part was choosing a classification method for each dataset. It needed to represent the data well and be visually understandable. In a different map it might not have been too bad, however, in such a small map with a large extent, sacrifices had to be made to keep from having legend values that couldn't be seen because they were such small countries (I learned after I was already design committed that you can choose to add text or insets to address such issues). So I went with Quantile as it provided a decently well-rounded visual of the values, even if a few outliers were mixed in rather than being in their own classes. The second hard part for me was getting the value ranges to display labels the way I wanted and still accurately reflect the data. I'm still working on understanding that part. Finally, and maybe the hardest, was getting all the information to fit on the map. While we had the option of using pictographs for our proportional/graduated symbols, I decided to stick with circles as I felt my map was crowded enough. I've seen some good (and bad) uses of pictograph symbols though, so definitely worth exploring more later. While this may not be the most exciting map I'll ever make, I think it is a fair shake at two new concepts and a lot to fit into one map.

Exploration of Choropleth mapping and graduated symbols using various European population data.