2. Encoding Data with the Hierarchy

Overview

Maps are a great way of visualizing geographic data. Learn how to create maps and use the hierarchy to maximize their effectiveness in this lesson.

To explore more Kubicle data literacy subjects, please refer to our full library.

Summary

  1. Lesson Goal (00:11)

    The goal of this lesson is to learn how to visualize maps effectively using the visual language hierarchy.

  2. How a Map Works (00:22)

    A map simply represents the location trait from the visual hierarchy.  Location refers to how information is positioned relative to other information, with relationships indicated by closeness or distance. Location is often represented as an x-y plot, and a map is just an x-y plot of latitude and longitude with an image in the background.

  3. Emphasizing Particular Values (01:33)

    Maps often use size to show data that has numeric values. Our brains associate small size with small values, which is fine when all values are positive. When some or all values are negative, using size is more complicated. It’s generally best to use color to distinguish between positive and negative values. You can then adjust the size scale so that the most negative values are smallest or so that values closest to zero are smallest.

    When a map uses size alongside location, we quickly notice the largest shapes, and ignore the smaller ones.

  4. Exploring Alternative Options (04:09)

    As an alternative to using size to identify points on a map, you can use gradients and shade relevant regions instead. Although this technically goes against the hierarchy, it may work if it makes the data come across more clearly.

    Another option is to use color to represent regions or other categories. Bear in mind that this should only be used with a limited number of colors. Another option is to replace these colors with shapes, but this tends to add too much complexity.

    A better approach to showing regions is to use a separate chart for each, effectively creating multiple smaller charts insead of a single large one. Taking this approach means that color is not needed to distinguish regions at all. Creating multiple charts may be more difficult, but you should try to avoid letting software defaults determine what visual you create.

Transcript

In the previous lesson, we briefly introduced the case studies we're going to consider in this course.

In this lesson, we'll learn how to visualize maps effectively using the visual language hierarchy.

In the hierarchy, location simply means how information is positioned physically to other information.

Closeness or distance is a very powerful way to see relationships.

The way most of us think about location is an X, Y plot.

You might also hear this called a scatterplot or scatter gram, but that sounds technical. To make sure your audience doesn't get confused or become uncomfortable, it's best to use simpler terms when talking about visualization. Let's convert this X Y plot into a map.

In a split second, you can see which states have the most or least activity.

Maps are one of the most used forms of visualization using the location trait.

When you think about a map in terms of the hierarchy, it's an X, Y plot of longitude and latitude with an image in the background.

That's why it's easy to interpret a map. It's literally just location.

Because the newest software makes it so easy to make maps, you're going to get a lot better at geography, but how can we make this map easier to understand? Let's explore a few options now.

Our brains automatically associate small size with small values, so we can use that to focus attention, but you must be careful, for numbers that are all positive, it's simple. When you have negative numbers, it's a little more complicated depending on whether you want to see the highest overall value or the highest negative value.

For a mixed positive and negative, there are even more options. This targets highest to lowest values.

Here, we are looking for the largest absolute values with zero in the middle, but there's a problem because without labels, how would you tell positive from negative? These are a couple safe alternatives to distinguish positive and negative.

You can use colors to emphasize the negative, the positive or both.

If we return to our map, we can see it combined size and location. Your eyes are drawn immediately to the larger circles and you process out the small circles. All this happens without trying, your brain takes care of it all.

Let's try moving down the hierarchy from size to gradient.

Now the highest values really stand out.

While generally, it's best to use the simplest traits in the least number of traits, your end goal is to make the data come across. In this case, gradients seem to do that better than size. Next, here's a way to use color for sales regions, and size for sales.

If you have more regions, it can really get colorful. So we only want to use this with a limited number of colors like we have here. The last map we'll look at swaps color for shapes, just to make a point that you should be aware of, when we talk about shape, that means different shapes. Using different sized circles is just one shape.

Let's see what happens if we use shapes instead of color for the regions.

Even with only four shapes, this is much harder to work with.

When you break this down based on the hierarchy, it's using the three traits of location, size and shape.

In this course, we'll use this little dinosaur symbol to mean don't do this.

While color for the regions is not a bad solution, it's always good to create the simplest view possible. Here's an approach that really works well and doesn't need color at all.

Regions act as the shapes, along with the headings.

We usually think of maps as a whole image, but we can break it up and have more control of the pieces. Depending on your visualization software, this might be actually be four separate visuals that together make one image about the data.

It's important to not limit your thinking based on defaults in the software. Sometimes it just takes a little imagination to push the boundaries.

This concludes our look at how best to visualize maps.

In the next lesson, we'll consider how to best represent numbers on a map, in particular considering how to represent positive and negative numbers.