1. A computer checking tool that is able to repeatedly process a plurality of data sets, each data set including data distributed according to a chosen statistical rule, the tool comprising: an estimator that is able to establish, for a data set, a value characterizing the reproduction, by that data set, of a criterion concerning the data contained there, a driver designed to call the estimator with a plurality of data sets in order to determine a plurality of values, and to establish a new plurality of data sets on the basis of said plurality of values, and to repeat the estimator ( 8 ) call each time with a new plurality of data sets previously established, until a condition is verified that involves an extremum of said plurality of values and/or number of repetitions. comprising a mixer that is able to establish a new data set on the basis of an existing data set, while maintaining the distribution according to the chosen statistical rule, and in that the driver is designed to call the mixer with at least some of the data sets as a function of a rule based on the plurality of values associated to those sets.