Day 1 · 9:30–10:15 · Instructional team

What is AI?

Big ideas + live demos — everything you need before you train your own AI at 10:30.

🐱 🐶 🐱 1000s of examples pattern finder “CAT!” ✓ answer

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?
A NORMAL PROGRAM 📜 human writes the rule follow steps answer AN AI 1000s of examples 🧠 it finds the rule itself

Secret #1

To a computer, everything is numbers

a photo = a grid of pixels one pixel = 3 numbers R 232 · G 141 · B 58 0.2  0.8  −0.4  0.6  −0.1  0.5  −0.7  … a sound = a long list of 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.
CATS 🐱 DOGS 🐶 the wall the AI learns ? new photo — which side?

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.
🤔 GUESS probably bad 📏 CHECK how wrong? (the error) 🔧 ADJUST a tiny nudge downhill 🔁 ×1,000s every lap around the loop = a little less wrong

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.
1 KNOB: YOUR SHOWER 🚿 cold hot 🥶 too cold 🥵 too hot 😌 just right 2 KNOBS: TRAIN THE LINE 📈 tilt ↻ slide ⇄ every nudge = these two knobs turning

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.
every possible knob-setting → how wrong (error) ↑ ☁️☁️☁️☁️☁️ 🌫️ fog — it never sees the map you (the AI) the slope under your feet = the “gradient” best possible AI

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

🏜️ flat — no signal 🌫️ lying, bumpy ground 🕳️ stuck in “pretty good” 📏 too-big steps bounce the true bottom
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

TRAINING PHOTOS every cat it ever saw was black 🧠 “cats are black!” an orange cat 🧠 ✗ “not a cat?!” one-sided examples → a one-sided AI. That’s “bias.”

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
how hard for AI how hard for YOU easy! hard! play perfect chess ♟️ hard! easy! tie a shoelace 👟
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.
🤖 🌍 act watch & predict

🤖 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 🔬

webcam ✊ ×30 ✋ ×30 ✌️ ×30 your examples training… ✌️ 97% live guess — try to break it!

Recap

Six things you now know

123456 🐱🐶 examples 7 2 90 4 18 3 6 numbers boundary 🔁 guess·check·adjust downhill in fog 🪞 data is the teacher

Questions? 🙋

? ?! 💡 every question makes the room smarter

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