Using Venn diagrams for qualitative data visualization

by | May 3, 2022

Presenting data in a comprehensive and compelling way to your audience is a key skill for intelligence professionals. While many clear rules exist for quantitative data analysis, data visualization for qualitative data sets takes more effort and thought to execute well, despite the many analytical models available. This post dives further into one of the analytical models you can use for qualitative data visualization: The Venn diagram.

What is a Venn diagram?

A Venn diagram is a way to visualize overlapping data sets. Typically, two or three concepts exist and are represented by circles. The overlapping sections of the circles represent the intersections between the concepts. Not sure how this might work? This video provides an easily digestible overview of the concept. Most importantly, a Venn diagram must represent all potential intersection combinations, otherwise it is not a Venn diagram, but rather a Euler diagram.

While Venn diagrams turn up regularly in memes across social media, and are useful in qualitative data analysis, they have their origins in mathematics.

John Venn – Inventor of the Venn diagram (or not?)

Venn diagrams are named after John Venn, a mathematician born in 1853 in the UK. Venn published a book in 1881, titled Symbolic Logic. In this book, Venn detailed overlapping circles used to represent properties of sets and subsets – what would come to be known as Venn diagrams.

While Venn’s name is attached to it, Venn is not solely attributable for the concept. Before Venn was Euler, responsible for the Euler diagram. A Euler diagram is like a Venn diagram but does not necessarily show all possible intersections of the sets (note that in the diagram below the yellow and orange sets do not overlap).

Before Euler, thirteenth century mystic Ramon Llull tried his hand at drawing circles to show interconnected concepts.

Related to all of this, is Boolean logic, a concept laid out by George Boole, a contemporary of, and inspiration for John Venn, and something used daily by the team at HelloInfo. Boolean logic is a mathematical concept, that relies on three operators – OR, AND, and NOT. It forms the basis of database searches and enables the efficient retrieval of information. It is easy to conceive of John Venn and George Boole having a drink and discussing these concepts at length. At the end of the night, they return home, and apply them differently – Venn to a visual diagram, and Boole to a logic-based algebra concept that contributes to the design of digital computer circuits.

Suffice it to say, while John Venn’s name is attributed to Venn diagrams, the concept is not his alone.  

What do Venn diagrams have to do with qualitative data visualization?

Venn diagrams (and Euler diagrams!) are a great way to visualize interconnected insights, and nicely present findings in a digestible way.

In recent HelloInfo engagements, Venn diagrams were used to show: 

  • The interconnected decision makers involved in technology purchase decision making
  • The overlap between product offerings of several competitor companies
  • The commonalities between customer needs for platform software solutions

While Venn diagrams are a nice, clean way to visualize information, one must be careful to represent the concepts correctly. If you are building 3 or 4 concept Venn diagrams, it is especially important to make sure the concepts you are overlapping make sense, and you are not breaking the logic of the diagram. Consider using a Euler diagram if you are struggling with this.

Hopefully you now know a little more about Venn diagrams and can potentially apply them to qualitative data, and have a laugh at this joke.

Interested in learning more about Venn diagrams, Boolean operators, or how HelloInfo can support you in your research and data visualization? Schedule a call with us.

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