In decision theory, a kind of puzzle in which whenever an ideally rational epistemic agent is awoken from sleep, it has no memory of whether it has been awoken before. Upon being told that it has been woken once or twice according to the toss of a coin, once if heads and twice if tails, it is asked its degree of belief for the coin having come up heads.

(statistics) The problem of interval estimation and hypothesis testing concerning the difference between the means of two normally distributed populations when the variances of the two populations are not assumed to be equal, based on two independent samples.

A puzzle of this kind: "You are given two indistinguishable envelopes, each containing money; one contains twice as much as the other. You may pick one envelope and keep the money it contains. Having chosen an envelope at will, but before inspecting it, you are given the chance to switch envelopes. Should you switch?" Because you stand to gain twice as much money if you switch while risking only a loss of half of what you currently have, it is possible to argue (fallaciously) that it is beneficial to switch.

Synonym of boy or girl paradox

The problem that a person or entity serving as an agent for another, and able to make decisions on the other's behalf, may be motivated instead to make decisions that benefit themselves.

Alternative form of first world problem

The situation where an autonomous robot is carried somewhere and as a result has trouble in determining its own location.

Synonym of starlight problem

(psychology) The phenomenon of autistic and nonautistic people mutually failing to understand each other due to cognitive differences in expressing and processing emotion.

(quantum mechanics) The general name for a vast category of physical problems pertaining to the properties of microscopic systems made of many interacting particles.