In-Depth Interview (IDI)

An In-Depth Interview, or IDI, is a type of qualitative research involving a personal interview with a single respondent. These are conducted one on one (1:1), although there may be hidden observers (as supports). These should be conducted by a highly skilled interviewer. The purpose of in-depth interviews is to understand the underlying motivations, beliefs, attitudes, and feelings of respondents on a particular subject or brand. These are in contrast to focus groups, which have multiple respondents in a group, along with one moderator, who is facilitating a group discussion.