#IronViz Again

Apr 5, 2019

Klaus Schulte

This week, I published this viz on the Earth Overshoot Day as my entry for the #IronViz European Qualifier 2019 (click to play with the interactive Version on Tableau Public).

OVERSHOT - IronViz Europe 2019

So why entering #IronViz again, after winning the competition last year? For mainly three reasons…

1. The Topic

For this qualifier entrants are invited to create vizzes on the topic of energy & sustainability. I personally think that implementing a sustainable usage of resources to operate the human economy within Earth’s ecological limits is one of the biggest challenges mankind is facing these days. We are becoming more and more aware of the impact that global climate change and unsustainable behavior have on our daily lives – no matter where we live.

Data and data viz can help people to gain a deeper understanding of the topic and give strong arguments against people still denying this threat. Furthermore, we as a dataviz community, can support organizations working on this important topic.

Footprint Network auf Twitter: "WOW! Check out the data vis by @ProfDrKSchulte. Thank you for diving into our data! #MoveTheDat… 2019-04-05 10-25-15.jpg

2. The Learning Opportunity

#IronViz is just a fantastic learning opportunity. While I have been on my Tableau & data viz journey for almost two years now, last year’s #IronViz Europe competition was a milestone for my technical (and personal) development. While #makeovermondays or #workoutwednesdays challenges are like sprints, that I love to do regularly, #IronViz is more like a deep dive covering all aspects of a data analyst’s live: searching data, preparing the data, analyzing and finding stories in it, designing the viz and pointing out the story, the ‘so what?’.

Furthermore I’m always challenging myself with every viz I create, trying new chart types or new techniques. For this project in particular I had the idea of a proportional world tile map, I wanted to focus on table calculations and to create a newspaper style long/wide form viz.

The Map

OVERSHOT - IronViz Europe 2019.png 2019-04-05 10-54-08

For the map, I was building up on work on world tile maps I first saw in visualizations by Neil Richards. To execute my idea of a proportional world tile map I used the technique of gridless grid charts, that I described in a blogpost some weeks ago (‘Get Rid of the Grid‘). While the linked post is describing the technique with line charts, I’m using multiple bar charts in this viz, that are actually gantt bars sized by the negative value of the measure I’m displaying here (the change of overshoot index vs. 2005).

The main advantage of a grid map is that all countries have the same size. This is killing the effect, that large countries or states dominate the view, e. g. referred to as the ‘Texas-effect’. You can find grid maps using different shapes like circles, rectangles or hexagons. In a ‘normal’ grid map you lose the size option, most of the time you don’t want it anyway. However, in a gridless grid chart, the size option is back. And it helps to identity in this case the countries with the largest footprints or biggest biocapacity very easily. Even with many overlapping bubbles, like for example in Asia, it is no problem to identify the accompanying country in the center of the bubbles thanks to the grid structure on top of them. Another advantage of this kind of map is that we are able to show change over time using the bars (or lines).

When you want to create own proportional (world) tile maps, make sure to sort the bubbles in the right order (big bubbles at the bottom, small bubbles on top) and to reduce the opacity of the bubble color, to make overlapping bubbles visible.

Table Calculations

Yes, I’ve been recognized as a Tableau Zen Master earlier this year, but I still feel more like a Zen Student, being aware of that there is still a lot to learn.

I wrote some weeks ago about my first serious steps with table calculations. I have used them before only randomly and most of the time it was a rank-calc. I know of course what lookup and first() and last() can do for me, but this #IronViz project was a good opportunity to dig deeper.

I realized this when I took a first look at the data, and saw that it was pivoted.

footprint:nfa-2018-edition | Workspace | data.world 2019-04-05 13-36-19

My first impulse was to unpivot the data, but I resisted and ended up using (nested) table calculations for almost all calculations I needed for my viz.

Tableau - Overshot #IronViz Europe 2019 2019-04-05 13-39-06.jpg

I really feel that I made one step forward with table calculations.

Viz Format

I normally don’t do long or wide form formats. I just feel uncomfortable when this is all I can see of my dashboard:

Tableau - Overshot #IronViz Europe 2019 2019-04-05 13-46-38.jpg

That’s why I normally use a dashboard size that fits my screen.

To handle this I created a lot of image exports during the creation process to check the positioning of the objects and the overall flow. A pleasant side-effect was that I was able to create this little clip to show the evolution of my viz in fast motion.


3. It’s a competition!

Competing with data rockstars from all over the continent is just fun! There are still some days left to enter, give it a try!

Thanks for reading,