Final answer:
Depth interviews are unstructured personal interviews used to uncover a respondent's deep-seated motivations and feelings on a topic.
Step-by-step explanation:
The method described in the question is known as Depth interviews. These are unstructured, direct, personal interviews wherein a single respondent is probed by a skilled interviewer to uncover underlying motivations, beliefs, attitudes, and feelings on a topic. Unlike structured surveys or questionnaires, depth interviews allow for more open-ended and spontaneous conversation, enabling the researcher to explore the subject's thoughts in greater detail and with greater flexibility.