手法を比較

	経時的深度インタビュー	詳細インタビュー
分野	調査方法論	質的手法
系統	Process / pipeline	Process / pipeline
提唱年	1990s–2000s (as a formalised qualitative method)	Mid-20th century (formalised in qualitative social research from the 1950s onward)
提唱者	Rooted in qualitative longitudinal research traditions; systematised by Johnny Saldana	Rooted in sociological interviewing traditions; systematised by researchers including Steinar Kvale and Herbert J. Rubin
種類	Qualitative longitudinal data collection technique	Qualitative research method
原典	Saldana, J. (2003). Longitudinal Qualitative Research: Analyzing Change Through Time. AltaMira Press. ISBN: 978-0759103917	Kvale, S. (1996). InterViews: An Introduction to Qualitative Research Interviewing. Sage. ISBN: 978-0803958203
別名	repeated in-depth interview, longitudinal qualitative interview, panel qualitative interview, longitudinal IDI	IDI, semi-structured interview, unstructured interview, qualitative interview
関連	5	6
概要	Longitudinal in-depth interviewing is a qualitative data collection technique in which the same participants are interviewed in depth on multiple occasions across a defined time span. By revisiting the same people over weeks, months, or years, researchers can trace how experiences, identities, attitudes, and meanings change — something a single interview cannot reveal. It is widely used in life-course research, health studies, education, and social policy.	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.