Adversarial information retrieval

Adversarial Information Retrieval is like a game where two people (or computers) try to find the best answer from a list of options. One person or computer (the 'searcher') looks through all of the possible answers and chooses the best one. The other person or computer (the 'adversary') tries to guess which one the searcher will pick. The searcher wants to pick an answer that the adversary won't be able to guess and then the adversary needs to guess which one the searcher chose so they can win the game.