Although Venn diagrams are sometimes associated with our younger years, these super simple, circle-based diagrams are useful in many aspects of adult life. Named after John Venn, who conceived the notion in around 1880, Venn diagrams visually portray the relationship between two or more sets of things so you can quickly see differences and commonalities in various groups or categories of information. Perhaps because they are so simple yet so handy, Venn diagrams have remained in diagramming vogue for well over 100 years. Not bad for an old, bearded, British guy.
There are several types of Venn diagrams. Here are a few examples of what you can create using Gliffy:
Separate Set Venn Diagrams
Separate set Venn diagrams are good for comparing two distinct sets of things that do not overlap. This is particularly useful for getting a quick overview of size. Imagine you wanted to create a presentation showing how many people in your company were within 5 years of retirement age. You’d start by finding out how many of your coworkers fell into the 59 and under group and how many were 60 plus. You would have two distinct groups with no overlap. Armed with these numbers, you’d be able to create a Venn diagram and quickly see how big one segment is relative to the other.
EXPERT TIP: To make your diagram proportionally representative, make the height and width of your circles match your numbers. For example, if you had 215 people under fifty-nine and 78 people sixty and up, you'd double click on your circle and adjust the width and height of one to 215 and the second to 78. Your two circles would then be proportionally representative of the two group sizes.
Subset Venn Diagrams
Subset Venn diagrams can be used to show that all members of a smaller group share a certain attribute with all members of the larger group, but not vice-versa. This could come in handy if you for example wanted to show what portion of your English-speaking clientele also speaks Spanish. You’d start by drawing one large circle with a smaller circle inside. The larger circle would represent English-speaking clients, while the smaller circle would include only people who spoke both languages. Even a person who didn’t understand Venn diagrams would quickly understand your point.
Intersecting Venn Diagrams
If you need to see the differences and commonalities between several sets of things, an intersecting Venn diagram is for you. The common project management notion of Cheap, Fast and Good (or Cost, Time and Quality) makes for a great real-world example. The idea is that you can have any two of the three, but never all three attributes at once. If you want high quality it’s either going to cost you time or money. If you want something done fast it will cost more. You will never be able to get something that’s fast, cheap and good. (Draw this diagram for your boss the next time he or she asks you to do something that you know is impossible.)
To create an intersecting Venn diagram, draw three circles that overlap in the middle. You’ll be able to show which attributes are unique to each circle, which overlap between two, and which are common characteristics of all three groups.
Three or More Set Venn Diagrams
Finally, you can create Venn Diagrams that are a blend of several of the above.
Imagine putting together a schedule for a preschool. You have kids that get dropped off early, kids that get picked up late, kids that get dropped off early and picked up late. And then you have a last group of kids that just come during regular hours. That took a lot of words to explain. It would have been much easier with a Venn diagram ;p
As you can see, Venn diagrams are easy to create and can quickly explain complicated ideas. Best of all, you don’t have to channel Mr. Venn to draw them. Just choose Venn diagram from the dialog box in Gliffy and get started. (Or just click this big, tempting, orange button.)