One of our areas of expertise is creating visualisations, especially visualisations of data. How do we do that? Daniël Staal can tell you more about that. He works at CAS as a data visualizer. In this interview, Daniël explains what a data visualist does, how he fulfils his role at CAS and why he enjoys his job so much.
Are you curious about the visualisations Daniël develops with colleagues? Check out the CAS Visualisation Showreel.

What do you do as a data visualist? Do you make those pie charts and bar graphs?
Yes, but data visualisations consist of so much more! You can use the most extraordinary forms. And that is also the hardest part: daring to go beyond your own imagination. Sure, some data fit well with a traditional bar or line graph. But if you really want to attract attention, a visualisation with its own unique shape works best.
Just look at the two data visualisations below. On the left is Simon Scarr’s visualisation “Iraq’s bloody toll”. It shows the number of deaths between 2003 and 2011 in the Iraq war. This visualisation is more than just an inverted bar graph: it also looks like a bloodstain. So very thematic and it immediately grabs attention!
On the right you see the visualisation of the Global Carbon Footprint. Each circle represents a country. The larger the circle, the larger the carbon footprint of that country. Together, the circles form a footprint. This type of visualisation is also called data art. The goal of data art is to convey emotions to the audience by showing insights, patterns or stories hidden in the data in an accessible and creative way.

How do you like being a data visualizer at CAS?
It is varied, creative and challenging. It’s a search for the perfect visualisation every time:
- It has to give the best insight into the data we are using for the project.
- It has to be visually appealing.
- It must suit the target audience and the message should become clear to them quickly.
- The time it takes to create the visualisation must fit the available budget.
We have a small technical team so we go through the whole process of data visualisation together. We also learn how to further improve this process. We do it all by ourselves. That’s what makes the work so much fun. We move from a good idea, to a nice sketch, to the technical skills, to make the visualisation a reality.
As a data visualizer, how do you collaborate with other colleagues? When are you asked to create a data visualisation and how do you go about meeting that request?
Colleagues ask me to join a project when they need a data visualisation. This can be a map, a graph, a dashboard, an infographic or another form. With the entire project team, we first brainstorm and try to answer the following questions:
- What is the purpose of the visualisation?
- What should you learn from the visualisation?
- Is the visualisation intended to persuade?
- Is the visualisation supposed to incite action?
- Is the visualisation intended to present a particular point of view? Or is it just meant to explore the data?
- Which visual form suits the data and the purpose best?
- What is the optimal way to show the data: a standard bar or line graph or some other form?
- Will the visualisation provide the desired insights and answer questions?
Then, either by myself or with colleagues, I make a number of sketches. We start with sketches because this allows us to easily make adjustments to the design. This sketch is already as close as possible to the final result. Once we have started programming, it is more difficult to change course. Once the project team and possibly the external party are satisfied with a sketch design, we start developing. The technical team starts coding the tool. During development, we regularly solicit feedback from the project team. When we are almost done, we establish a domain name where the final visualisation can be seen.
What visualisation would you like to show yourself? One where you went beyond your own imagination?
I am currently working on a data visualisation that provides insight into forest fires in Europe. I visualized the data in the form of a burning tree. Below is an image of the visualisation.

The trunk of the tree represents Europe. The trunk branches into eastern, northern, southern and western Europe and then into the different countries. The thickness of the trunk and branches indicates how many forest fires have occurred in that area. The thicker, the more forest fires. In the outer branches – the branches representing countries – you can see different fires. These are the forest fires that have raged in the different countries in recent years. So the more forest fires there have been in a country, the worse the branch will be on fire. A visualisation like this is not the easiest to read, but conveys a strong feeling. This is an example of data art. This visualisation is still under development. When it is finished, I will add the link here!