Data Viz Done Right

January 15, 2019

Tableau Tip Tuesday: How to Compare Current YTD to Prior YTD

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This week's tip came from a question from Andrzej Szczurko on week one's tip from Lorna:

How would you do year to date percent difference when you only have data for first 3 months in the current year? For example when you have data for the current year from January to March for 2018 and you want to compare it to January to March from 2017 and calculate percent difference then?

This is a very common business question. In this video I show you how to use level of detail expressions to calculate these two fields plus the difference.

NOTE: In the video, I have the Year over Year calculation backwards. The formula should be: SUM([CY Sales])-SUM([PY Sales])

January 14, 2019

Makeover Monday: Workers Making Minimum Wage or Less in America

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For Makeover Monday week 3, the Community is making over the viz below from Business Insider. I had bookmarked this data set back in 2016 and stumbled across it again over the weekend. I was then able to get more data from the Bureau of Labor Statistics for 2002-2017. Win!

What works well?

  • Maps are easy to understand
  • Positioning of Alaska and Hawaii in the available space
  • Including notes about the data in the footer
  • Simple, effective title
  • Using a single color gradient; a diverging palette would not be appropriate

What could be improved?

  • Ranges are not the same size
  • Smaller States are nearly impossible to compare; this is a good use case for a hex or tile map
  • No context for good vs. bad

What I did

  • Looked at the data over time
  • Included a comparison to the US average for context
  • Included all States for context
  • Allowed the user to highlight the State they are interested in
  • Included labels on the ends to the lines to show change over the entire period

January 6, 2019

Makeover Monday: How Has Press Freedom Changed Around the World?

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For week 2, Eva chose this visualization from Freedom House about the changing freedom of press in countries around the World.

What works well?

  • The colors contrast well and represent the values well (i.e., green = good, etc.).
  • The map zooms in nicely as you select a region across the top.
  • Good tooltips
  • The white borders around each country make them easy to distinguish.
  • Using dots to represent the small islands.

What could be improved?

  • Without using the zoom feature, small countries are very hard to see.
  • The title doesn't really tell me what the data map is about.
  • You can't see trends over time. In other words, you don't know if the press are getting more or less free.
  • There are no definitions for what the scores mean, unless you hover over a country.

What I did

  • I started by building a trellis chart that showed every country and its score over time. It was so messy and crowded so I scrapped it.
  • I wanted to see the overall trends, so I focused on the percentage of countries within each year that fall into each status.
  • I used the same color palette.
  • I wanted to show the change vs. 1993, so I included that as text on the end of each line.

I found this to be a particularly interesting, and a bit alarming data set. According to this data, the Press are becoming less free. That's not good for democracy.