What is the theory of secretary?

The secretary problem, also known as the marriage problem or optimal stopping problem, is a mathematical theory that addresses decision-making under uncertainty. It involves selecting the best candidate from a sequence of applicants, where you must choose one and cannot return to previous candidates once they are passed over. The optimal strategy typically suggests that you should interview a fixed number of candidates (about 37% of the total) without selecting any, and then choose the next candidate who is better than all previously interviewed. This approach maximizes the probability of selecting the best overall candidate.