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Module 1 Summary: LLM Foundations

ConceptKey Point
LLMNeural network trained on internet-scale text to predict the next token
Language ModelAssigns probabilities to sequences of words
TokenizationConverts text into numbers (tokens) the model can process
Context WindowMaximum number of tokens an LLM can process at once
  • Parameters vs Data ratio: Modern LLMs have ~2 tokens of training data per parameter
  • Context window growth: 512 (GPT-1) → 2048 (GPT-3) → 128K (GPT-4) → 1M (Gemini 1.5)
  • Token ratio: ~0.75 words per token (English)
  1. Explain why an LLM is considered a “prediction engine” rather than a “thinking machine.”
  2. What happens to the probability of the entire sequence as you multiply conditional probabilities?
  3. Why can’t you use raw word IDs as tokens? What’s the vocabulary size problem?
  4. If a model has a context window of 128K tokens, and each token is ~4 characters, how many pages of text can it process? (Assume 3000 characters per page)
  1. What does LLM stand for?

    • a) Large Logic Machine
    • b) Large Language Model
    • c) Linear Language Module
    • d) Latent Learning Model
    • Answer: b
  2. Which of the following is NOT an emergent ability of large language models?

    • a) Chain-of-thought reasoning
    • b) In-context learning
    • c) Database querying
    • d) Code generation
    • Answer: c
  3. What is the primary purpose of tokenization?

    • a) To encrypt the input text
    • b) To convert text into numerical IDs
    • c) To compress the input
    • d) To translate between languages
    • Answer: b
  4. What happens when you send a prompt longer than the context window?

    • a) The model expands its context window
    • b) The prompt is truncated (oldest tokens dropped)
    • c) The model crashes
    • d) The output doubles in length
    • Answer: b
  1. Q: What is the difference between a foundation model and a fine-tuned model?
  2. Q: Why do larger models show emergent abilities that smaller models don’t?
  3. Q: Explain autoregressive generation in one sentence.