A research method in which the real-life behavior of a pre-selected individual or a few individuals is studied at an in-depth level for some time through the use of observation, interviews, and writings (such as letters) is the ________ method of research.

A) correlational
B) case study
C) naturalistic observation
D) survey

The case study method involves intensive in-depth study of a few individuals, and typically uses a combination of observation, interviews, and examination of documents or artifacts related to the person being studied. Options A, C, and D refer to broader approaches to research that do not necessarily involve focusing specifically on one or a few individuals in detail.