The Venn diagram, also known as a set diagram, is one of the the most basic and easily understood methods for depicting logical relationships between sets of data. By a young age, most children are able to compare and contrast sets of objects using a Venn diagram – and it remains one of the most recognizable constructions around.
For this fact, we have John Venn to thank. An English-born logician and philosopher, Venn is credited with establishing his now-famed diagrams in an 1880 paper called On the Diagrammatic and Mechanical Representation of Propositions and Reasonings.
Though it's most definitely the case that constructions like Venn diagrams were used for centuries before John Venn, they bear his name because he was the one to popularize and standardize their usage.
Everyone knows how a basic Venn diagram works. One circle (A) contains a data set – let's say 'fruits'. It contains all the fruits known. Another circle (B) contains a different data set – let's say 'red objects'. These two sets together form the union of (A) and (B), containing all fruits and red objects. Where the two circles meet (at the intersection) is where you'll find things that are both fruits and red objects – apples, strawberries, tomatoes, etc.
Of course, Venn diagrams can feature many more than two data sets. Those are much more fun.
Google has honored the mathematician with an interactive doodle on its homepage. Venn, born August 4th, 1834, would be 180 years old today.
You can choose from five different groups on each circle, for instance 'musical' and 'spiral-shaped'. Google will then produce something that is both musical and spiral-shaped.
Go check it out. It's Monday – you've probably been productive enough already. Give yourself a break.
Images via Wikimedia Commons, Google