MACHINE LEARNING DEVICE, MACHINE LEARNING METHOD, AND MACHINE LEARNING PROGRAM

A domain adaptation data richness determination unit (52) determines, when a first model trained by using training data of a first domain is trained by transfer learning by using training data of a second domain, a domain adaptation data richness based on the number of items of training data of the second domain, the first model being a neural network. A learning layer determining unit (54) determines a layer in the second model, which is a duplicate of the first model, targeted for training, based on the domain adaptation data richness. A transfer learning unit (56) applies transfer learning to the layer in the second model targeted for training, by using the training data of the second domain.