The Science of Privacy on public Toilets

Johannes schreibt mir: „In einem Paper (PDF) wird mathematisch aufgearbeitet, welches Urinal man am besten wählen sollte, um möglichst lange Freiraum neben sich zu haben. Es sind tatsächlich nicht immer die äußeren!“

A man walks into a men's room and observes n empty urinals. Which urinal should he pick so as to maximize his chances of maintaining privacy, i.e., minimize the chance that someone will occupy a urinal beside him? In this paper, we attempt to answer this question under a variety of models for standard men's room behavior. Our results suggest that for the most part one should probably choose the urinal furthest from the door (with some interesting exceptions). We also suggest a number of variations on the problem that lead to many open problems. […]

Our main conclusion is that when faced with the decision of what urinal to choose upon entering the men's room, in order to maximize your privacy, you should probably choose the one furthest from the door if it is available and the one next to it is unoccupied. For a vast majority of the (what we consider) natural behaviors that men choosing urinals might follow, this choice is optimal (in the sense dened above). Beyond this observation, we feel that this problem leads to many interesting variations that are worthy of investigating further and we encourage everyone to do more of their thinking while using public restrooms.

The Urinal Problem (PDF, danke Johannes! Bild via Shutterstock)