The idioms that end a game of 成语接龙
In 成语接龙, the idiom chain game, some idioms leave the next player nothing to say. Here are the dead ends and two-move...
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How many ancestors did you have a thousand years ago?
Doubling every generation gives you about a trillion ancestors a thousand years back, more people than have ever lived....
One Singapore quarter, two official growth rates, four times apart
In August 2020 the economy had shrunk 41.2% in the second quarter; in October the same quarter was a 13.2% contraction....
The annual Sharpe ratio hides an assumption about your returns
Annualising a monthly Sharpe ratio by multiplying by the square root of twelve is not a unit conversion. It is Andrew Lo...
A distress-zone Z-score does not mean a 70% chance of bankruptcy
The Altman Z-score's famous 70% is the share of firms that DID fail which had scored in the distress zone — a sensitivit...
Why your DNA ancestry estimate is vaguer if you are Asian
A result full of "Broadly" labels is telling you something real, but not about your ancestry. One company's own document...
Why two websites give you different life path numbers
Numerology has two standard ways of doing the arithmetic, and for about one birthday in eight they disagree. The dispute...
When a DNA match could be your grandparent or your half-sibling
A match sharing around 1,700 centimorgans could be a grandparent, an aunt or uncle, or a half-sibling. The averages for...
Why Your Best Performers Get Worse
A thousand simulated pages whose true conversion rates never change. Selected on one period's numbers, the top tenth app...
What Happens When You Test Twenty Metrics
A dashboard rarely shows one number. Simulated with nothing real to find, examining twenty metrics produced at least one...
How Big Does an A/B Test Need to Be?
Sample size is usually decided by how long someone will wait. Simulated across a grid, a genuine one-point lift on a ten...
What Happens When You Check an A/B Test Early
Twenty thousand simulated experiments with no real difference in them. Read once at the end, 4.9% came back significant,...
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