In-Depth Interview — In-Depth Qualitative Interview

The in-depth interview is a one-to-one qualitative data-collection method in which a researcher engages a participant in an extended, open-ended conversation to elicit rich, detailed accounts of experiences, perceptions, beliefs, or meanings. Unlike structured surveys, the interview guide serves as a flexible road map rather than a fixed script, allowing the researcher to probe unexpected directions as they emerge. The approach is foundational to qualitative inquiry and is used directly as a primary method or as the data-collection arm of phenomenology, grounded theory, narrative analysis, and other frameworks.