Perception & Illusion 3: Do You Believe What You See?

How does our brain complete our understanding of what we can see?

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Identity and diversity


Lesson plan


60 minutes

This lesson plan for pupils aged 7–11 looks at illusions. It encourages them to investigate whether they can always believe what they see – and to reflect on this in their everyday lives.

Through a series of activities and visual prompts, including artworks and the classic ‘Kanisza triangle’ optical illusion, pupils will explore how our brains fill in the gaps of a scene or make ‘best guesses’ when information appears to be missing.

Developed for Dreamachine by A New Direction with the British Science Association, this 10-page lesson plan is one of three ‘Perception & Illusion’ resources for pupils aged 7–11. It includes prompts for questions and discussions, plus links and resources for further learning.

Lesson plan

Curriculum links

Science: Working Scientifically
Key Stage: KS2

Northern Ireland:
The World Around Us: Interdependence
Key Stages: KS1, KS2

Sciences: Experiences, Outcomes
Levels: First Level, Second Level

Science & Technology: Principles of Progression, What Matters
Progression Steps: PS2, PS3