Applied AI

Course map · S1 How LLMs work · Episode 11 of 12

When is a reasoning model worth the cost?

S1 E11 Decision framework · 17 slides · 8 October 2026

  1. Slide 1 of 17, Cover.
  2. Slide 2 of 17, Why it matters.
  3. Slide 3 of 17, Mental model.
  4. Slide 4 of 17, Concepts.
  5. Slide 5 of 17, Your turn.
  6. Slide 6 of 17, Data.
  7. Slide 7 of 17, Data.
  8. Slide 8 of 17, Data.
  9. Slide 9 of 17, Data.
  10. Slide 10 of 17, Concepts.
  11. Slide 11 of 17, Concepts.
  12. Slide 12 of 17, Where it breaks.
  13. Slide 13 of 17, For engineers.
  14. Slide 14 of 17, In practice.
  15. Slide 15 of 17, For leaders.
  16. Slide 16 of 17, Decision rule.
  17. Slide 17 of 17, Series map.

Lesson notes

Reasoning pays only on tasks that hold several steps in mind at once, so keep it low by default and prove each increase with a paired test.

Decision rule

Keep reasoning at its lowest setting by default. Turn it up per task, only where a paired test on your own items shows it earns its tokens and seconds.

Ideas in this lesson

  • Token cost
  • Reasoning
  • Measuring, not quoting
  • Latency

Take it further