Vizible Difference

Christine suggested me to have a look at Simpson's Paradox, following my recent posts on Anscrombe's Quartet and Datasaurus Dozen. They are all about learning to look at statistics in an impartial way.

Simpson's Paradox is about the difference between the stats of an entire data set and the stats of the same data set sliced by a dimension. They can be quite different or even contradictory. We can't take one for the other.

We are going to show some visualization techniques to compare the whole vs the parts through two examples.

UC Berkeley Admission Gender Bias

The data is from here. From the campus total percentage, we see that the admission rate is 39%. Then men's rate is 45% and women's is 30%. So it seems that there is a campus wide bias against women.

This post is about 13 data sets, known as Datasaurus Dozen, that have the same stats and different distributions. Stats can be deceiving while data visualization can makes a big difference.

Inspired by Anscombe's quartet and Alberto Cairo's Datasaurus, Justin Matejka and George Fitzmaurice crafted another 12 datasets which have the same stats and different distributions. Thus the Datasaurus and the Dozen.

Francis Anscombe, a British statistician and a professor at Princeton and Yale, constructed 4 different sets of data which all have the same stats, known as Anscombe's quartet. However the quartet's data distributions are quite different. 

Stats alone can be deceiving. Through data visualization, we can gain powerful insights into their differences. 

So, I decided to render Anscombe's quartet in Tableau. All calculations are based on Tableau's native functions.

In a single day, I am asked twice the same question: how to install database drivers for Tableau in Mac? The question of the day is regarding the drivers for Presto and PostgreSQL databases. The docs online may not answer the question exactly. 

Here are the exact steps:

Search the driver in question and download it to your computer. It's usually in the form of a .jar file.Open your Mac Finder and copy the .jar file.Hold the Option key and click the Finder menu Go.

There are always more than one ways to skin a cat. In Tableau, there is always one more way to design the same chart. Mastering them will give us more options to satisfy the various requirements we may be asked for.

Line chart is one of the most basic ones. Yet we can draw them in more ways than we care of. But there are many intricacies that are interesting to master.

I almost named the post as Charting "Top N and Others" via Post-filtering. Read on to understand why.

Visualizing "Top N and Others" is an often required business use case. A popular solution is by creating a top N set. That's the one I have been using through the years.

I wrote a post in the context of a pie chart back in 2014 on grouping those smaller slices into 'Others'. 

Recently, I encountered an issue at work. The dashboard won't let me using set.