Probability Belongs to the Argument
A card pack, a whist hand or a patient has no probability of its own; the number measures the proportion of cases in which inferences of a given form carry truth with them.
Put that way, speaking of an event's probability without naming the condition under which it is supposed to happen says nothing at all, however universal the habit of so speaking. A friend's count of a hundred and sixty-five whist hands made the point against the calculation: real packs carry traces of the last deal that no formula allowed for. And because a ratio settles only across thousands of trials, the single case considered by itself has no probability whatever.
- probability
- statistics
- chance
- averages
- conditional-probability
- multiplication-rule
- independence
- gambling
- measurement
- inference
- mathematical reasoning
Enter a dialogue
- A man draws one card from a nearly all-red pack: red is heaven, black hell. If probability means long runs, why is choosing that pack sensible?
- A friend counted spades in 165 dealt hands of cards and found 94 with three or four where arithmetic promised 85. Why did the arithmetic go wrong?
- A patient is told an operation has a ninety per cent success rate. On your account, what has actually been told to them?
- If every probability statement needs its condition named, most of what people say about chance says nothing. What survives the pruning?