[hlieberman]

It’s not just the UK who has standardized on these language; the U.S. intelligence community also has a list of required terminology to use for different confidence levels and different likelihoods — and distinguishing between them. It’s all laid out in ICD-203, publicly available at https://www.dni.gov/files/documents/ICD/ICD-203.pdf

I’ve found it very helpful in the same vein as RFC 2119 terminology (MUST, SHOULD, MAY, etc.); when you need your meanings to be understood by a counterparty and can agree on a common language to use.

[bo1024]

Interesting. This terminology really makes no sense without more shared context, in my view. For example, I would not describe something that happens to me every month as a "remote possibility". Yet for a 3% chance event, repeated every day, monthly occurrences are what we expect. Similarly, someone who describes events as "nearly certain" would surely be embarrassed when one of the first 20 fails to happen, no?

[randallsquared]

A 1-in-a-million chance seems quite remote, yet if you are rolling the dice once a millisecond...

This applies to any repeated chance, so it probably doesn't need to be called out again when translating odds to verbal language.

[bo1024]

I'm not only talking about repeated events, though. If someone told me about 20 different events that they were almost certain, and one failed to happen, I would doubt their calibration.

[Nevermark]

19 out of 20 could easily mean they get 119 right out of every 120 “almost certainties” and they just rolled a 1 on a die 6 for the “luck” component.

One off, 1 out of N errors are really hard to interpret, even with clear objective standards.

And emphasizes why mapping regular language to objective meanings is a necessity for anything serious, but can still lead to problematic interactions.

Probability assessments are will almost always sometimes certainly could be considered likely hard!

[MichaelZuo]

I think the parent was suggesting a much higher percentage for “almost certain”… like >99.9%

[handsclean]

The terms aren’t causing this confusion, it’s that you’re applying them to less specific subjects, in particular omitting periods. “3% chance per day” makes sense, “remote chance on any particular day” makes sense, “remote chance” does not make sense, “3% chance” does not make sense. You’d also need to say “nearly certain over any 30 day period”, though if the odds are 3%/day then it’s only (just into) probable, not nearly certain—60%. It’d have to be 10%/day (not a remote chance, but highly improbable) to be nearly certain (96%) over 30 days.

[bo1024]

Well, this is why I started by saying "without more shared context"

[voidUpdate]

If something happens to you every month, that's a certainty. If it has a 3% chance to happen to you on any given day, its a remote possibility that it will happen to you on any given day