This is the final exam for Occam’s & Hanlon’s Razors. It pulls everything together: what Occam’s razor really says (and the two things people get wrong), the arithmetic of why fewer assumptions win, Hanlon’s “incompetence before malice” and the biases it corrects, and — most important — exactly where each razor lies to you. Take your time. A few questions look easy until you spot the trap.
How this exam works
Read carefully — this exam is final. Each question appears one at a time. Once you submit an answer it is locked for good: there’s no going back, no retry, and no restart. Your score is hidden until the end, where you’ll see a pass/fail verdict. The pass mark is 70%. A few questions ask you to select all correct answers.
What does Occam’s razor actually tell you to do?
Select an answer to continue.
Course Recap
Big picture
The two razors, in one picture
- Occam’s & Hanlon’s razors
- Occam’s razor
- Among explanations that fit equally well, fewest assumptions wins
- Simpler, not simplest-at-all-costs
- Why fewer assumptions win
- Assumptions multiply: 0.7 × 0.7 × 0.7 ≈ 0.34
- More moving parts → more ways to be wrong
- Hanlon’s razor
- Incompetence before malice
- Occam pointed at human motives
- Fixes the fundamental attribution error
- When the razors lie
- Occam over-trims complex systems (Hickam’s dictum)
- Hanlon excuses patterned, self-serving harm
- Weight by stakes; a razor is a prior, not a proof
- Occam’s razor
Key takeaways
A razor is a rule of thumb that shaves off unlikely explanations to give you a smart first bet — a prior, never a proof. Occam’s razor prefers the explanation that fits the facts with the fewest assumptions, and the arithmetic backs it up: independent assumptions multiply, so every extra one can only drag the joint probability down. Hanlon’s razor is Occam pointed at people — reach for incompetence before malice, because a screw-up needs no plan while a plot needs intent, competence, and coordination all at once. But both razors lie when you trust them blindly: Occam over-trims genuinely complex situations (remember Hickam’s dictum), and Hanlon excuses patterned, one-directional, self-serving harm. Hold each as a starting bet you actively test, update on evidence, and lean on less as the stakes rise. Used that way, the razors make you faster and less wrong; used as verdicts, they’re just a blindfold you sharpened yourself.