How to create a scatter plot
The scatter plot is perfect when you want to show the relationship between two quantitative measures. Each dot of the chart is placed on a coordinate grid according to its values of two categories. The scatter plot is a mathematical diagram that is also very prominent in social sciences. At first sight, it might appear confusing and somewhat overly complicated. But once you learn how to read it, it's easy to spot the correlation of two variables without having to do the math.
This guide will show you how to create a scatter plot with Datawrapper. The scatter plots you can create are feature rich and fully responsive, meaning they will adapt to different screen sizes. This example shows you how the purchasing power of a country relates to its internet speeds.
Notice the diagonal black line. This line helps you to identify the correlation of the two categories (purchasing power and internet speed). It is called the trend line. The line is determined by the arrangement of the dots. This line has two properties: direction and strength.
- A line starting in the lower left and rising to the upper right (/) indicates a positive correlation, meaning: when a increses, b increases.
- A line starting in the upper left and dropping to the lower right (\) indicates a negative correlation, meaning: when a increases, b decreases and vice versa.
- The strength of a correlation is indicated by the angle of the line
- If the dots are scattered all over the place, not showing a scheme, and if most parts of the coordinate grid are vacant, don't use a trend line. There simply might be no correlation!
Don't forget to tell your readers how to read a scatter plot! Be award that correlations and specifically causation are often confused. There are numerous examples where wrong conclusions have been drawn.
1. Preparing and importing the data
You can copy & paste data from Excel or the web, or upload your own CSV files. For example, here is the dataset that powers the chart above. Your dataset should be formatted as follows.
You can copy the full data from a Google Doc we prepared: Here's the dataset.
Note how the data set should be structured:
- One header row containing labels
- The first column defining labels of the dots
- The following two columns contain values of seperate categories that will be used as x- and y-coordinates thereby defining the positions of the dots in the chart
- The values do not have to be of the same measure
Once your dataset looks like this, you can copy it into Datawrapper and click "Upload and continue".
2. Check & Describe
Finally, make sure that the box " First row as lable" is ticked so that Datawrapper correctly assigns the values to the labels. Click on "Proceed" and Datawrapper will take you to the next step.
The chart type to choose here is the " scatter plot". Experienced users of Datawrapper will know that, but if you just started it is important to know that with the selection of this chart type, the options and features available for this chart will change in the sections Refine, Annotate, and Design. We cover this in a separate short tutorial found here.