#TweakThursday 19: ASCII as Data Marks

ASCII (and Unicode) characters can offer a variety of lightweight data marks. Judicious choices of context-sensitive data marks can create more interest in the eyes of the viewer and lead to better visualizations.

Especially in tooltips, we are limited to using ASCII/Unicode characters. Some of them can be used as data marks to provide data visualizations. ASCII art have been around for a long while. With ASCII, we can create very expressive art form if we dare to be creative.

For example, in restaurant ratings, we have seen expressions like

• Expensive: $$$
• Moderate: $$
• Cheap: $

Depending on countries and being consistent with context, we can replace the above $ by € or ‎¥.

In various ratings such as movies or product reviews, we have seen stars being widely used.

• ✰✰✰✰
• ✰✰✰
• ✰✰
• ✰

So this is not something new. What is new is we can use them in Tableau's tooltips to create lightweight data visualization that complements and enhance the primary charts. This has been advocated by Andy Cotgreave. Recently new Zen Master Rody Zakovich showed some more tricks. Especially the formula Replace(Space(),' ','█') is very convenient for creating a long string of any character. 

In a recent viz of the day on 10/18/2016, I found that the vertical bars are hard to compare in height between Clinton and Trump numbers. This can be remedied by adding a little ASCII chart in tooltips.

Note that we used ▲ and ▼ as data marks to represent upward/downward trends. Also we added green color for up and red color for down. This seems more context sensitive than the bar chart based on '█'.

That concludes the tweak today. Click the images for interactive versions.