The document discusses in-depth interviews as a method for qualitative data collection in research. It provides definitions of in-depth interviews and notes that they involve one-on-one, unstructured or semi-structured conversations to allow participants to freely discuss their experiences and perspectives on a topic. The summary describes how in-depth interviews can be useful for obtaining detailed first-person accounts and exploring topics in depth, but require skill from interviewers in actively listening, asking probing questions and guiding the discussion.