Tableau Intro Viz
Here is my first viz. It's based on the Tableau Intro Course here. It's very simple.
The first step is to download the Excel file they provide in the course. After loading it to Tableau, we select the cleaned data tab and build a visualization off of that.
Making the viz is quick and easy. First, on a new tab, drag the Country Name field onto the Tableau canvas, which brings up a world map and puts a dot on it for every country in the dataset. Then, drag the CO2 Per Capita field onto the canvas, which changes the sizes of the dot to represent CO2 emissions per capita in each country.
After that, click on the "Color" button to change the color of the dots. This makes it easier to recognize color values - not only can we see dot size, we can see color. Initially I wanted to create a diverging color scheme without white in the center, but some quick Google research quickly revealed that’s only possible with editing the preferences.tps file. I'm not intimidated by that but I don’t want to do get too far down the rabbit trail on my first viz, so I continued without taking that step.
Next, I filtered the data to the most recent year, which in this case was 2011.
At this point I noticed one country in this "cleaned" data wasn't recognized. The value was "Korea, Dem. People’s Rep.". This meant Tableau didn’t know where to map it. I fixed the reference using the Tableau interface and it showed up properly as North Korea.
Then, I charted CO2 Emissions Per Capita over time by opening a new tab, double-clicking CO2 Emissions Per Capita, double-clicking Year, and then dragging CO2 Emissions Per Capita to the "Color" button to add a color to each line. I select the same color scheme as on the first tab.
Finally, I combined both charts on a new Dashboard tab. I set overall formatting to automatic size, set each viz to a size that fit well in the dashboard, added a title, and uploaded. You'll see it below.
Please notice in the top viz on this dashboard that the USA has a red circle. If you watch the first intro video linked above, at 3:27 you can pause and see their video has the USA as a light grey. That’s because I adjusted the “middle” of the diverging colors. The default is set to the middle of the data, which is about 22 metric tons of CO2 emissions per year per capita. I shifted the center from 22 metric tons to 12 metric tons of CO2 per year to make the USA appear worse. The point isn’t to make some big political statement – rather, just to emphasize how data (or its presentation) can be manipulated to tell one truth or another (and to show that I'm not mindlessly following an instruction video without thinking about what I'm doing).
NOTE - shift+click to drag the map! Clicking without shift will only allow you to select the data.
Anyway, creating dashboards in Tableau is about more than just presenting data. It's also about exploring data. Take a second to click on Kuwait on the world map. Notice anything about the data over time?
My first instinct was that it may have to do with Operation: Desert Storm, but that ran from 1990 to 1991, and the data is missing in 1992 through 1994, before reappearing in 1995. Some quick internet research Iraq formally accepted the UN-demarcated Kuwait border in November, 1994. During this time, all Iraq data is present, but perhaps the border controversy made it difficult to measure Kuwaiti CO2 emissions in the interim.
No matter what the cause, it's a great example of the power of business intelligence tools like Tableau - with the right data, a few mouse clicks can reveal information that could take hours to find by browsing a spreadsheet.
Hope you enjoyed! More to come.