HOW MANY PEOPLE PAY THEIR TRAM FARES
Abstract Many experimental situations lead to inverse sampling schemes with some random or non-random stopping rule, since at each experiment only a bounded number of observations can be made. This note discusses the problem of estimating the unknown probability in the underlying geometric distribution of such schemes. I encountered this problem in a very special context, that of estimating the proportion of non fare-paying passengers in a local transportation system. This aspect is stressed throughout, and some special terminology arising from this is used.