Consider that high quality experiments furnish data that relate proper time intervals to coordinate time intervals for different values of the relative velocity (life time dilationf moving mesons). An inteligent computer program could find out the best function of the relative speed which relates all the experimental results, i.e. the time dilation formula. Could we use it for further relativistic derivations or it is necessary to perform other experiments (light clock) in order to derive it? We find a simillar situation in the case of the formula which accounts for the mass dilation (Bucherer's experiment).