Depth Interview/dɛpθ/ /ˈɪntəvjuː/

Also known as an individual interview or (especially in the USA) a 'one-on-one', this is a qualitative market research interview with a single respondent. Such interviews vary greatly in content and interviewing approach as well as in dimensions such as length (from a few minutes to several hours) and location (respondent's own home or other location).