Big ideas + live demos — everything you need before you train your own AI at 10:30.
The one-sentence recap
AI = a computer that learns from examples
A normal program follows a recipe a human wrote.
An AI is shown many examples and finds the pattern itself.
Today's question: HOW? What actually happens inside?
Secret #1
To a computer, everything is numbers
🖼️ A photo = a giant grid of numbers (how red, green, blue each dot is)
🔊 A sound = a long wiggly list of numbers (the wave)
📝 A word = a list of numbers too (we'll see this in the ChatGPT session!)
🤔 Quick guess: how many numbers is ONE selfie? …about 36 million. Your selfie = 36 million numbers in a trench coat 🕵️
So "finding a pattern" really means: finding a rule about numbers.
Secret #2
Learning = drawing a boundary between groups
Imagine plotting every example as a dot: cats here, dogs there.
Training = finding the line (or curvy wall) that separates the groups.
A new photo comes in → which side of the wall does it land on? That's the answer.
Let's watch a real AI draw that wall — live, right now.
Teach the Machine 🧠
LIVE GAME
Drop blue & red dots, then watch the AI color the whole map. Try: few examples vs many · a weird example in the wrong place.
Secret #3
How does it improve? Guess → check → adjust
1️⃣ Make a guess (probably bad at first)
2️⃣ Check: how wrong was it? (the "error")
3️⃣ Adjust a tiny bit to be less wrong
🔁 Repeat thousands of times
AI doesn't start smart. It starts terrible and gets less wrong, over and over.
Train the Line 📈
LIVE GAME
The AI nudges the line every time it makes a mistake — watch guess → check → adjust happen in real time.
Wait — adjust what, exactly?
Every AI is a machine covered in knobs 🎛️
🚿 Your shower has 1 knob. Brrr… too far… OWW… back a bit… ahh. You feel, you nudge, you repeat
📈 "Train the Line" has exactly 2 knobs: one tilts the line, one slides it. Every nudge you just watched = those two knobs turning
🤖 ChatGPT? The exact same machine — with a trillion knobs 😅
"Training" is no more mysterious than this: turn the knobs until the answers stop being wrong.
You Be the AI — Two Knobs 🎛️
LIVE GAME — YOU DRIVE
Turn 🎛️ Tilt and ⇄ Slide until the wall separates blue from red — the background color is your "how wrong" meter. Go green… then hit 🗺️ Reveal the knob-map.
Inside the "adjust" step
Training = hiking down a mountain of mistakes
🎛️ Two knobs → a map: knob #1 = east–west, knob #2 = north–south. Every spot = one knob-setting
⛰️ Altitude there = how wrong the AI is. So walking = turning the knobs!
🎯 The best possible AI lives at the lowest point
🌫️ The catch: thick fog — it only feels the slope under its feet
Feel the tilt → step downhill → repeat. That's gradient descent — grown-up word #1. It's just a fog hike.
Find the Lowest Point 🌫️
LIVE GAME — YOU EXPERIMENT
You're the AI: blind in the fog, feeling the slope, with a limited step budget. Try all 5 landscapes — and figure out what makes each one HARD. Experiment: small vs large steps · the 🎲 random jump · then watch the 🤖 AI demo walk the same ground.
What did you discover?
Why finding the bottom is genuinely hard
🕳️ A cozy little valley trapped you — grown-up word #2: a local minimum. "Pretty good" blocks the road to "best"
🏜️ Flat ground = your feet feel nothing — no slope, no clue, no GPS
〽️ The canyon: falling in is easy — crawling along its almost-flat floor eats your whole step budget
🌫️ Bumpy ground lies — the little dip under your foot isn't always the real way down
📏 Big steps overshoot the bottom · tiny steps run out of budget — and no, there's no perfect step size (engineers argue about this DAILY)
🎲 Your best escape: jump somewhere random and retry — real AI training does exactly this. Professional randomness 😄
GPT trained exactly like this — feeling its way downhill in fog, on a map with a trillion knob-directions.
The teacher matters
Data is the teacher — good or bad
Show it only black cats → it thinks all cats are black
Show it only sunny-day photos → it fails in the rain
Show it unfair examples → it learns the unfairness ("bias")
Rule: an AI is a mirror of its examples. Choose them carefully.
A strange truth
Hard for you ≠ hard for AI
🤖 Easy for AI, hard for you
Multiply huge numbers · search a billion pages · play perfect chess · never get bored
🧒 Easy for you, hard for AI
Tie a shoelace · get a joke · know a stack of chairs is climbable · tell when a friend is sad
Walking is harder than chess. That's why robots are the frontier.
The AI family
Three kinds of AI you'll meet this weekend
🏷️ Classifiers
Sort things into groups. "Cat or dog?" — what you just watched, and what you'll build in the lab.
✨ Generators
Create new stuff. "Write me a story" — this afternoon's ChatGPT session.
🤖 Agents
Predict & act in a world. "Push the ball into the goal" — tomorrow's world-models session.
After the break · 10:30
YOU train an AI — no code, 20 minutes 🔬
Tool: Teachable Machine (runs in the browser)
Pick classes: ✊ rock / ✋ paper / ✌️ scissors — or clap vs snap
Feed it examples from the webcam or mic — 30+ per class
Test it live — then try to BREAK it (weird angle, new person, messy background)
Breaking it is the best part — every failure teaches you what data was missing.
Recap
Six things you now know
1️⃣ AI learns from examples, not recipes
2️⃣ To a computer, everything is numbers
3️⃣ Learning = drawing a boundary between groups
4️⃣ It improves by guess → check → adjust — nudging its knobs 🎛️
5️⃣ Adjusting = hiking downhill in fog — traps and all (you lived it!)
6️⃣ The data is the teacher — bias in, bias out
Questions? 🙋
Then: break — and at 10:30, you train your first AI.
Mini-games hub for later: ask a TA for the QR · Teach the Machine, Train the Line & Find the Lowest Point are all on it