Venn Diagram

What is a Venn diagram?

A Venn diagram is two or more overlapping circles used to compare things. What belongs only to one goes in that circle's outer part; what belongs to both goes in the overlap. In reading, the two circles are usually two characters, and the overlap is what they have in common however different they look on the surface.

They are named after John Venn, the Hull-born Cambridge logician who introduced them in an 1880 paper on representing propositions diagrammatically. He designed them for formal logic; primary classrooms borrowed them, which is why they work best when the question really is about sets and not about a general chat.

How do you compare two characters with a Venn diagram?

1. Pick two characters who are not obvious opposites. Hero versus villain produces two full outer parts and an empty middle. Two allies, or two rivals who want the same thing, produce a much better lesson.
2. Fill the outer parts first, and fast. Five minutes, no discussion. This is warm-up, not the work.
3. Now do the middle, slowly, with the book open. Every entry needs a moment in the text behind it.
4. Challenge one thing in each outer part. Ask whether it is really unique — often it belongs in the middle and nobody had looked.
5. Finish with one sentence: what does the overlap tell us about the book?

Why do children only fill in the differences?

Because differences are visible and similarities are inferred. A child can see that one character is old and one is young. Seeing that both are lying to protect somebody requires holding two parts of the book in mind at once, which is a genuinely harder thing to do.

So the empty middle is not laziness — it is the diagram telling you exactly where the comprehension work is. Treat a thin middle as the start of the lesson rather than a finished piece.

What else can you compare in a Venn diagram?

• Two settings — the camp and the town, the island and home.
• One character, twice — who they were in chapter one against who they are at the end. This is the strongest version for upper primary.
• The book and the film. Popular, and it teaches adaptation choices rather than plot.
• Two texts on the same subject — excellent for non-fiction and for spotting bias.
• A character and yourself. Uncomfortable, revealing, and best kept voluntary.

Which year groups is a Venn diagram for?

Year group	What to change
Years 1–2 (Grades K–1)	Compare two very familiar characters and accept single words. Sort word cards physically into hoops on the carpet before ever using paper.
Years 3–4 (Grades 2–3)	Full activity with the word bank. Require one piece of evidence for anything in the middle.
Years 5–6 (Grades 4–5)	Drop the word bank, apply the quota, and use the same-character-twice version. Then ask them to write a paragraph from it — the Venn becomes a plan.

Is a Venn diagram the same as a Carroll diagram?

No, and the difference is useful. A Venn diagram sorts by membership — things can be in one set, the other, both, or neither. A Carroll diagram sorts by two yes-or-no questions at once in a grid, so everything lands in exactly one box. If your comparison has genuine overlap, use a Venn. If it splits cleanly along two criteria, a Carroll diagram will show it more clearly.