1. A method for preventing overlearning of a model in which a plurality of teacher data is comprised of a plurality of training data each including a pair of a training input value and a training output value and further comprised of a plurality of verification data each including a pair of a verification input value and a verification output value, and wherein learning of said model is performed by repeating a step of receiving a training input value and a step of adjusting a calculation method in said model so that a training output value obtained by the calculation method on the basis of said received training input value approaches to a training output value in each of said training data, said method comprising the steps of: first calculating a first error between the training output value obtained by performing the calculation method in said model on the basis of a received training input value and the training output value; second calculating a second error between a verification output value obtained by performing an adjusted calculation method in said model on the basis of a verification input and the verification output value; concurrently displaying said first and second errors on display means; repeating said first and second calculating steps and said display step as a learning process of the model until a comparison of said first and second errors indicates an overlearning of the model; and stopping said repeating steps in response to a user's instruction based on said displayed errors.