An Exploratory Data Analysis Using Tableau

Formatting your Data

You may need to format your data before you start, like I had to with the data sheet I tested. Ensure that the first row of your spreadsheet is the names of the variables or indicators. The data should begin in the very next row.

Each row should have only one piece of data, too. You might find Tableau’s Excel Plugin useful for transforming your data if, for example, you have data for each year in its own column that you need to reformat. I used it to transpose the population data from my sample set into separate rows. 

Once the data is downloaded Tableau Public and upload your data, you’ll notice that Tableau has separated your data by sheet.

Drag-and-drop a sheet you want to work with into the box labeled ‘Drag your sheets here’ and the data within the sheet will appear, and Tableau Public will see the data types you’re working with.

Next click the big orange ‘Go to Worksheet’ button and give Tableau a few seconds to process your data.

Choose a Dimension (qualitative data, typically described with words) and a Measure (quantitative data, described with numbers) you want to look at. For example, drag the Year dimension and Country Names into Columns, and Population into Rows. It’s not visually-useful quite yet, but it’s getting there.

It needs filtering, because right now this data set mixes in income demographics with continents with countries with the world total, and other groups of countries.

You can filter your data by dragging Country Name onto the Filters field.

I was curious about the populations of the countries who are currently members of the United Nations Security Council, so I filtered my set to:

• People’s Republic of China
• France
• Russian Federation
• United Kingdom
• United States
• Argentina
• Australia
• Chad
• Chile
• Jordan
• Lithuania
• Luxembourg
• Nigeria
• Republic of Korea
• Rwanda

You can also filter by the year, so that only the time frame you’re concerned with is covered in your visualization.

Types of Visualizations

With a data set like the one demonstrated in this article, you can create a wide variety of visualizations. One of the nice things about Tableau Public is you don’t even need to imagine the possibilities yourself – it has a feature called ‘Show Me’ that will highlight some of the options that could be interesting for your data types.

You can show how a variable like population changes over time with the Line Graph.

The Filled Map tool will let you start to show geographically where larger and smaller populations are through colour intensity.

If you just want to communicate relative size of populations though, you can always use Packed Bubbles, where of course, the bigger the bubble, the bigger the population.

Saving and Exporting

You can save individual sheets, or you can save ‘Stories’ which pull together multiple sheets to show how the data looks when visualized in different ways. To create a Story, in the top menu, go to Story > New Story.

Give your story a name that represents the overall message you want to convey – what’s the point of the set of graphics?

Next drag a sheet from the left (Dashboards and Worksheets) into the area labeled Drag a Sheet here, and then give it a caption.

Each of the sheets becomes like a page that your reader can turn to to see a different aspect of your data set.

Best Tools For Creating Screenshots Compared

Final Visualization