MODEL LEARNING APPARATUS, MODEL LEARNING METHOD, AND PROGRAM

There is provided a model learning technique for learning a model which performs classification into three values by model learning using an AUC optimization criterion. A model learning unit is included which learns a parameter ψ{circumflex over ( )} of a model by using a learning data set based on a criterion which uses a predetermined AUC value, the learning data set being defined using normal data generated from sound observed in a normal state and abnormal data generated from sound observed in an abnormal state, and the AUC value is defined from a difference between an abnormality degree of the normal data and an abnormality degree of the abnormal data using a two-stage step function T(x).