premise: For an experiment to qualify as a binomial experiment , it must have four properties : ( 1 ) there must be a fixed number of <mask> , ( 2 ) each trial must result in a `` success '' or a `` failure '' ( a binomial trial ) , ( 3 ) all <mask> must have identical probabilities of success , ( 4 ) the <mask> must be independent of each other .
hypothesis: the proper context for <mask> here should be the act of testing something