Subject estimation system and method

It is possible to provide a subject estimation system and a subject estimation method, and the like that can be highly accurate in estimating the subject of the conversation even when the learning data is insufficient. A subject estimation system includes a convolutional neural network (10) to estimate a subject label of a dialog. The convolution neural network (10) includes: one or more topic-dependent convolutional layers (12) and one topic-independent convolutional layer, each of the one or more topic-dependent convolutional layers performing, on an input of a word-string vector sequence corresponding to dialog text transcribed from a dialog, a convolution operation dependent on a topic, and the topic-independent convolutional layer performing, on the input of the word-string vector sequence, a convolution operation not dependent on the topic; a pooling layer (13) performing pooling process on outputs of the convolutional layer (12); and a fully connected layer (14) performing full connection process on outputs of the pooling layer (13).