Applied AI

Course map · S2 Retrieval and RAG · Episode 1 of 16

Why retrieval exists

S2 E1 Explainer · 16 slides · 17 October 2026

  1. Slide 1 of 16, Cover.
  2. Slide 2 of 16, Why it matters.
  3. Slide 3 of 16, Why it matters.
  4. Slide 4 of 16, Mental model.
  5. Slide 5 of 16, Worked example.
  6. Slide 6 of 16, Concepts.
  7. Slide 7 of 16, Data.
  8. Slide 8 of 16, Concepts.
  9. Slide 9 of 16, Data.
  10. Slide 10 of 16, Where it breaks.
  11. Slide 11 of 16, Where it breaks.
  12. Slide 12 of 16, For engineers.
  13. Slide 13 of 16, For leaders.
  14. Slide 14 of 16, Where this goes.
  15. Slide 15 of 16, Decision rule.
  16. Slide 16 of 16, Series map.

Lesson notes

Retrieval hands the model the right passage at the moment of the question, which fixes stale and private facts but moves the failure to search.

Decision rule

Use retrieval when the answer lives in your own data. Then log what it retrieved, and measure search and answer separately.

Ideas in this lesson

  • Cosine similarity
  • Context
  • Grounding
  • Retrieval

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