Venn Diagrams
A visual comparison tool using overlapping circles where learners place items that are unique to each category in the outer sections and shared characteristics in the overlapping centre.

A venn diagrams diagram
What is venn diagrams?
- Draw two or three overlapping circles, each labelled with a category
- Learners identify characteristics unique to each category and place them in the outer sections
- Characteristics shared between categories go in the overlapping sections
- Discuss what the overlaps and differences reveal about the topic

A venn diagrams diagram
How it works
Venn diagrams make comparison visual and structured. Each circle represents a category, and the spatial arrangement forces learners to think carefully about whether a characteristic belongs to one category, another, or both. The overlapping section is where the most interesting thinking happens, because placing something in the overlap requires recognising a shared quality between two apparently different things.
Two-circle Venn diagrams compare two items. Three-circle diagrams compare three, with additional overlapping sections where two or all three circles meet. The three-circle version is significantly more challenging because learners must consider multiple overlaps simultaneously.
The tool works across subjects. In Science, compare two habitats, two materials, or two organisms. In Humanities, compare two historical periods, two cultures, or two geographical locations. In Languages, compare two characters, two texts, or two genres. In Mathematics, classify numbers, shapes, or data sets.
Venn diagrams are particularly effective for challenging assumptions. Learners often begin with strong ideas about what makes two things different. The overlap section forces them to find similarities they had not considered, which develops more nuanced understanding.
Classroom example
A Year 6 Humanities class in a Monmouthshire school is comparing life in Roman Britain and life in modern Wales. One circle is "Roman Britain," the other is "Modern Wales." Unique to Roman Britain: slaves, toga-wearing, Latin language. Unique to modern Wales: internet, cars, Welsh language. In the overlap: roads, central heating (hypocaust/radiators), organised government, baths. The class is surprised by how much sits in the overlap and discusses why some things have persisted for two thousand years.
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Venn diagrams develop the "Develop" strand of thinking skills through comparison, classification, and recognising patterns. They build cross-curricular literacy and numeracy through structured analysis and set theory, and work across all AoLEs wherever comparison and categorisation are valuable.
Rainbow Curriculum's Thinking Tools lens helps you plan where comparison tools are used across your curriculum, ensuring learners develop systematic approaches to identifying similarities and differences.
Tips
- Start with two circles before attempting three. Three-circle Venn diagrams are genuinely complex.
- Use large paper and physical cards that learners can move between sections as they discuss.
- A common pitfall: empty overlaps. If learners cannot find shared characteristics, the categories may be too different for meaningful comparison. Choose comparisons where overlap is likely.
- Challenge learners to fill the overlap section first, then the unique sections.
- Combine with double bubbles for a different visual approach to the same comparison task.
Source: Adapted from "How to develop thinking and assessment for learning in the classroom", Welsh Assembly Government, Guidance 044/2010.




