Given a speaker's conversation with others, it is required to recognize the speaker's personality traits through the conversation record, which includes two scenarios, (1) conversations: the robot recognizes the personality traits of the speaker through the conversation between them (e.g., psychological counseling), (2) conversations : the robot listens to the speaker's conversations with other people and then recognizes the speaker's personality traits (e.g., group chatbot, home service robot). Since includes the case of , we only discusses PRC in conversations. The task of PRC in conversations can be formulated as:
where is a 5-dimensional vector representing Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness. is the conversations between and ().