Training vs Using a Model

10 min read

An AI model has two stages in its life. First it is trained, which is slow and expensive. Then it is used, which is fast and happens every time you tap a button. Knowing the difference helps you understand how AI apps work.

New words

Training
The stage when a model learns by studying many examples.
Inference
The stage when a trained model makes a prediction for a new input.
Prediction
The answer a model gives for an input it is shown.
Train/test split
Keeping some examples hidden from the model, to use later as its exam.
Overfitting
When a model memorises its practice examples and fails on new ones.
Deploy
To put a finished model inside an app so people can use it.
Retrain
To train a model again on fresh data, because the old one is out of date.

What you will learn

  1. Learning to cook, and cooking dinner
  2. Training: learning from lots of examples
  3. Testing: the exam it has never seen
  4. Try it: memoriser or learner?
  5. Inference: using the trained model
  6. Try it: the model lifecycle
  7. Where you see it every day
  8. Explain it to a friend
  9. Key takeaways

10 quiz questions at the end.

Start this lesson

The full lesson, with interactive demos and the quiz, opens after you sign in with Google. It is free.

All lessons · Back to the roadmap