Today we explore gait analysis and eye-scanning technology — two fascinating ways computers can identify people.
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Key Questions for This Lesson
Tap each question to reveal the answer — try to think of your own answer first!
Q1
What is a gait?
✅ A gait is a person's distinctive way of walking — their stride length, speed, rhythm and posture.
Q2
What is the difference between iris and retina scanning?
✅ Iris scanning reads the coloured ring around your pupil (visible from a distance). Retina scanning reads the blood vessels inside the back of your eye (requires a special camera close to the eye).
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What You'll Do Today
6 activities covering gait analysis, how cameras identify your walk, iris vs retina scanning, a true/false challenge, and your personal reflection — finishing with a PDF export to submit on Google Classroom.
Activity 1 of 6
What is Gait Analysis?
Your walk is as unique as your fingerprint. Click each phase of the gait cycle to learn how computers analyse it.
Click each phase to learn what cameras measure:
🦶Heel Strike
⚖️Mid Stance
🚀Toe Off
🌀Swing
🦶 Heel Strike
The heel contacts the ground. Cameras measure the step width and foot angle. Even how hard you land is unique to you.
Where it's usedCCTV systems in airports, train stations, and shopping centres can identify you by gait alone — no face needed.
How accurate?Modern gait recognition systems achieve over 90% accuracy, even when subjects are wearing different shoes or carrying bags.
Why it's usefulUnlike facial recognition, gait can work at long distances and at angles where the face is not visible.
Can it be fooled?Deliberately changing your walk can reduce accuracy — but it's hard to maintain an unnatural gait consistently for long periods.
Activity 2 of 6
How Does Gait Recognition Work?
A gait recognition system has several stages. Drag the labels into the correct order to build the pipeline.
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Put the Steps in Order
Drag each stage into the numbered boxes below in the correct order (1 = first).
Stages — drag them into order ↓
📊 Extract measurements (stride, speed, arm swing)
🔍 Match against stored gait profiles
📷 Camera captures video of a person walking
🧍 Create a silhouette by removing the background
✅ Identify or flag the person
1
2
3
4
5
Think about it: Why might a gait recognition system struggle with someone who has recently injured their leg or changed their footwear?
Activity 3 of 6
Iris vs Retina Scanning
These are two very different types of eye-based biometrics. Learn the differences, then sort the facts.
👁 Iris Scanning
Reads the coloured ring around your pupil
📏Scanned from up to 1 metre away
💡Uses infrared light camera
🧩Pattern has ~266 unique features
🏥Non-invasive — no contact needed
✈️Used in airports, border control
🔴 Retina Scanning
Reads blood vessels at the back of the eye
📏Requires very close positioning (2–3 cm)
💡Uses low-powered infrared laser
🧩Blood vessel pattern is unique to each eye
🔒More accurate but less convenient
🏛️Used in high-security facilities
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Sort the Facts
Drag each statement into the correct column — does it describe Iris scanning, Retina scanning, or Both?
Facts to sort
👁 Iris Only
🤝 Both
🔴 Retina Only
Activity 4 of 6
True or False?
8 rapid-fire statements about gait analysis and eye scanning. Answer as fast as you can!
Question 1 of 8
Activity 5 of 6
Pros & Cons — Fill the Table
For each biometric method, add one advantage and one disadvantage in your own words. Think carefully!
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Gait Analysis
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Iris Scanning
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Retina Scanning
Challenge yourself: Can you think of a situation where retina scanning would be better than iris scanning, and vice versa?
Activity 6 of 6
Your Reflection
Answer these three questions thoughtfully — they will appear in your PDF report.
1
Which biometric method from this lesson do you think is most reliable and why?
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2
Gait analysis can identify people without their knowledge. Do you think this is acceptable? Explain your view.
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3
Name one real-world place where each of today's three biometric methods could be used, and explain why it suits that location.
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🎉 Lesson Complete!
Great work. Enter your name below, then click Export as PDF. Your report opens in a new tab — press Ctrl+P and choose Save as PDF.
6/6
Activities Completed
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True/False Score
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Sorting Activities
3
Reflections Written
Submitting: Your report will open in a new tab. Press Ctrl+P, set destination to Save as PDF, then upload the PDF to Google Classroom → Lesson 2 assignment → Add or create → File.