No. 248 · Evidence · Human Nature and Judgement
Occam’s Razor
When explanations compete, start with the simplest one that fits the facts.
In the Almanac
“Think horses, not zebras”, 1940s · “Waze”, 2013
Both stories in full, three ways to use it and where it misleads.
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Questions
What is Occam’s Razor?
Occam's Razor, named after the 14th-century philosopher William of Ockham, advises that among competing explanations we should prefer the one that makes the fewest assumptions. It does not guarantee the simplest answer is right, but it trims away needless complexity and points us to the most likely starting point.
How do you use Occam’s Razor?
When something puzzles you, list your assumptions and see which you can remove. Check simple explanations first, such as workload or unclear instructions when a colleague seems disengaged, before reaching for complicated theories. Add complexity only when the evidence demands it.
When does Occam’s Razor matter?
Occam’s Razor is one of the 68 mental models for evidence, the situations where you ask: Is this really true? Within that, it belongs to “Testing a claim”, alongside False Negative, False Positive and Falsification.
What is an example of Occam’s Razor?
Two stories show it at work: Think horses, not zebras (1940s) and Waze (2013). Both are told in full in The Mental Models Daily Almanac, which has two stories for each of its 365 models.
Which mental models are related to Occam’s Razor?
First Principles Thinking, Base Rate Fallacy and The Map is not the Territory. Occam’s Razor itself comes from human nature and judgement.