Which of the following represents a qualitative research method?

The choice highlighting an in-depth interview to explore personal experiences represents a qualitative research method because it focuses on collecting detailed, descriptive information about individuals' thoughts, feelings, and perceptions. This method allows for the exploration of complex social phenomena by providing rich, contextual data. In qualitative research, the emphasis is on understanding the meaning and interpretation of human experiences rather than quantifying them. In-depth interviews facilitate a deep dive into personal narratives, revealing insights that may not emerge from more structured quantitative methods.

Conversely, the other methods listed focus on quantifiable data and predetermined response options. Surveys with fixed response options limit the depth of understanding human experiences, while longitudinal studies emphasize collecting numerical data over time. Experiments, typically designed to assess cause-and-effect relationships, also align more closely with quantitative approaches. The in-depth interview stands out as a method that captures the nuance and complexity of human behavior, making it a quintessential qualitative research technique.