there is provided with a method , including : optimizing a first objective function defined by using an explanatory variable belonging an attribute in each sample , a target variable in each sample , and a first conversion parameter to find a value of the first conversion parameter ; generating by using the first conversion parameter corresponding to the attribute a conversion function for converting an explanatory variable belonging to the attribute to an intermediate variable with certain range ; optimizing a second objective function defined by using a plurality of the intermediate variables corresponding to the plurality of variables in each sample , the target variable in each sample , and a second conversion parameter to find a value of the second conversion parameter ; and generating by using the second conversion parameter a probabilistic model for calculating from a plurality of intermediate variables a probability that a predetermined event occurs or does not occur .