One of the great things about Tableau is that it’s been designed for anyone to be able to install and run insightful analyses within a matter of minutes. A drum teacher of mine used to say, “make the easy s*** look hard, and the hard s*** look easy,” and a lot of the time this is how people end up creating dashboards and vizzes that look impossible to the wider public. “Show me” is a feature of Tableau that can create those stellar vizzes with minimal effort. However, if you want to really understand the elements of what you create and how your data is being processed by Tableau, it’s best to learn how to create things without “show me.” This week, I will walk you through how you can create three charts from scratch in Tableau. These charts are more easily created with the show me option, but it’s a great learning process to open up the Tableau hood and check out what makes the engine run.
Today, I will demonstrate how to create a box-and-whisker-plot chart without the show me option.
Box-and-whisker plots are a great way to explore how dispersed your data is: you might find that you have a lot of points that cluster towards the median, or you might find that your values are widely dispersed between your maximum and minimum values. This can help build a starting point for deeper explorations of data.
When constructing a box-and-whisker plot, first drag your dimension to columns and your measure to rows. Next, change your mark type to a circle and drag the dimension that you want to base your points on to the detail card. In this case, I am breaking up my points by Order ID for each sub-category. For the sake of clarity, it is also helpful to resize your circle points so that the reference lines you are about to create will show up more clearly.
Next, create your reference band and reference lines. First, create the reference band for each sub-category (this is the cell level) based on quartiles. This will create a reference band with the middle split marking the median, the upper edge marking your upper quartile, and the lower edge marking your lower quartile. Make sure you turn off labels, uncheck show recalculated line, and feel free to format the bands to whatever color suits your weather.
Lastly, create two separate reference lines marking the minimum and maximum for each cell of your data.
Now you have a box-and-whisker plot created from scratch without the help of the show me panel. An added benefit of creating a box-and-whisker plot in this way is that you are free to customize the format of your lines, the shaded boxes, and even the references that the whiskers point to. In this example, we used maximum and minimum as the upper and lower whisker reference points, whereas Tableau usually creates whiskers that refer to points within 1.5 times the interquartile range. If you have no idea what any of that means, you can always stick to the max and min 🙂