 Unfortunately Fisher did not give a general definition of the fiducial method and he denied that the method could always be applied.His only examples were for a single parameter; different generalisations have been given when there are several parameters.A relatively complete presentation of the fiducial approach to inference is given by Quenouille (1958), while Williams (1959) describes the application of fiducial analysis to the calibration problem (also known as "inverse regression") in regression analysis.