Should a confirmation dialogue use Yes and No, or OK and Cancel?

Yes/No or OK/Cancel on a dialogue?

Neither, if a verb will do — and it almost always will. The accepted answer's reasoning is that people do not read dialogue text, so a button reading Yes is meaningless on its own, while one reading Delete or Save still says what it does without the sentence above it.

Why the verb wins

A button labelled with the action survives being read out of context, which is how buttons are actually read.
Yes and OK only mean something in combination with the message, so they require the message to have been read and understood correctly.
Someone familiar with the software wants to scan the buttons and proceed. A verb lets them; Yes does not.
Platform interface guidelines were cited in support of preferring a specific action word over a generic acknowledgement.

The failure case that makes the point

One answer supplied the example that settles it. A dialogue asking whether you really want to cancel your account, with buttons marked OK and Cancel, means that OK cancels the account and Cancel does not cancel anything — the word Cancel is doing two opposite jobs in the same box. No amount of careful message-writing rescues that. Buttons reading Close account and Keep account cannot produce the same confusion.

If you must use one of the pairs

One answer offered a workable division: a dialogue that asks a question takes Yes and No, while one that performs an action and may take input takes the action word and Cancel.
By that rule, Do you want to sign out? gets Yes and No, and Set the event time gets OK and Cancel.
The same answer's implicit point is that if you cannot tell which of the two your dialogue is, that is a sign the wording needs fixing before the buttons do.

The underlying assumption

The accepted answer rests on a claim worth stating plainly: nobody reads your dialogue boxes. Whether or not that is literally true, designing as though it is produces better dialogues — shorter messages, unambiguous buttons, and no reliance on the reader having parsed a sentence before choosing. Designing as though people read carefully produces the account-cancellation trap above.