What do we use when we want to show data on geographical space? “The map, that’s right!” Dora once said. This week is all about mapping software, specifically ArcGIS.
ArcGIS supports many different file type imports but the .csv is the one we’ll use. To me, csv files look like spreadsheets but not limited to a particular software like excel. The dataset I’ll be testing with is the Iowa Townships Data Codebook which I think will show the geographical location of homes in town when visualised on a map. In particular I’m curious to map the different occupations of the head of household. (I already expect to run into issues because I can see that the same job has different ways of being written in the file.)
After creating my first map in ArcGIS the different basemaps remind me of something. In my ancient Greek history class we have frequent map quizzes. The map I used to study on is a “Light Grey Canvas” as ArcGIS calls it, but the map on the quizzes are usually topological. Sure all the geographical elements are there but on the topological maps the mountains and cliffs (Greece is very mountainous) stand out spectacularly while on my study map they are just triangle lines to indicate mountains. I remember thinking “Where is that river valley?” because on the topological map it was overshadowed by the tall mountains.
The different visualisations create different effects like the ones that change size and colour based on how large a number is has greater visual impact but can obscure detail. You can significantly change the perception of a dataset with the visualisation, I mean even using red for one field and blue for another can affect perception that the red ones are more impactful. The large size can also make the other data from the larger points seem more important when that is only one data field and not necessarily related to other fields.
The pop-ups also influence the viewing experience because it can give data beyond what is mapped. Sometimes the pop-ups can show important data like the family’s names can’t be easily mapped because you would end up with hundreds of different categories. In the pop-ups there can also be written context for each point on a map that would be too long to show by default. I wish the pop-ups could be hover to show rather than click to show because the UI makes it unclear that you can click each point.
Accessibility when making a visualisation in ArcGIS is also important. Map creators should remember to choose a basemap that compliments their data, for example don’t choose the navigation basemap if you are mapping something related to the geography of the location. The creator should also remember the basics of making the data points a colour that stands out from the basemap (ArcGIS has blessed blend modes which makes this much easier for the same point colour on different map colors!). Ideally the colours should be colour-blind friendly (the most common is red-green colour blindness) and have appropriate contrast from other data point colours.
I feel very confident in helping someone figure out ArcGIS because the UI is pretty intuitive to me. I do with they had hover tooltips but I can figure out specific functions or code expressions with their documentation and google. One final thing I must remember to tell people is ArcGIS does NOT autosave.
