2Level 2 · Prepares round 2 of the league

Train your first model

Build an image classifier from your own photos in half an hour. Spend the rest of the level finding out where it breaks and fixing it.

≈ 5 hoursThe image lab beside each articleNo code at allTraining a model, zero code

What is inside

10 readings, 6 hands on exercises, and 2 quizzes across 4 modules.

You will be able to

Train, test, diagnose, and retrain an image classifier in the browser on your own.
Split data into a training set and a test set, and say why testing on training data is cheating.
Recognise overfitting from concrete signs, not from a definition.
Explain what a single training example is and why labels must mean the same thing every time.
Spot class imbalance and explain why 99 percent accuracy can still be useless.
Submit predictions as a labels file, the same format the competition round uses.

League round 2

Train Something

Round 2 covers exactly this level. Opens 19 February 2027, Friday to Sunday, pick your own slot.

Who it is for

You finished Level 1. You have a laptop or Chromebook with Chrome and a webcam, and a phone you can take photos with. No code.

Try it in blocks

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