This document provides guidance on how to conduct in-depth interviews (IDIs). It explains that IDIs are qualitative research techniques that allow for open-ended, one-on-one discussions to gain insights into people's thoughts, feelings, and behaviors. Effective interviewing requires building rapport, actively listening, adapting questioning based on the participant, using open-ended questions, and taking detailed but concise notes for later analysis and reporting. The document outlines best practices for each stage of the IDI process from preparation to note-taking.