Wednesday – day 3 of our Dashboard week challenge. We are working on Victoria Road Accidents data starting from January 2006, ending with October 2018.

We had couple of different data files related to this topic, all coming from The first challenge was to choose which fields to use among all of those in the 15 tables provided. Second challenge was to use Tableau Prep only for the data preparation. Until now we’ve been heavily relying on the powers of Alteryx, so switching to Tableau Prep was a bit of a challenge. Luckily the data was pretty clean, so this step mainly involved joining and filtering data. During the exercise, we figured out that Tableau Prep is excellent for data exploration.

For this dashboard I wanted to experiment with some of the new features in Tableau 2018.3. I used the density mark option and set action to make the information a bit more user friendly.

Using density is quite easy in Tableau. You just have to plot your data (for example on a map) and choose the option from the marks card. What I realized is that choosing the right coloring on a specific map makes a huge difference. Somehow having a dark color for less dense marks, popping color for middle density and white for the most dense areas is working really well with light maps.

In terms of bringing set actions to life, the process is fairly easy. First you have to go to your source sheet and create a set including all the data. Bring that set to filter or detail on both sheets – the source and the target one. When creating the set, you will have to specify the Source Sheet and the Target Set you’ve previously created. And it should be as easy as that.

There is a lot more to explore in terms of the practical application of Set Actions, but this was a good starting point.

To finish up the Dashboard I created custom legend and some instructions to help the viewer understand the visualization quickly and further interact with it.