Large Language Models

13 min read

A large language model, or LLM, guesses the next word again and again. At a huge scale, this simple game gives you a model that can chat, write code and summarise. In this lesson you see how an LLM is made, what "large" means and how to choose one.

New words

LLM
Large language model: a very big model that guesses the next token of text.
Pre-training
The first stage, where the model reads a huge amount of text.
Parameters
The numbers inside a model that it learns. They are also called weights.
Alignment
Training a model to be helpful, honest and safe, using human feedback.
Open-weight model
A model whose weights you can download and run yourself.
Knowledge cutoff
The date after which the model has seen no new text.
Benchmark
A fixed set of test questions used to compare models.

What you will learn

  1. One student who read every book
  2. Three stages: how an LLM is made
  3. What does "large" mean?
  4. Context window and knowledge cutoff
  5. Try it: a model card comparer
  6. Open-weight or closed? How people choose
  7. Why does an LLM sound sure when it is wrong?
  8. Benchmarks, and why your own tests matter more
  9. In a real system, and interview tip
  10. 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.

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