手法を比較

	経時的フォーカスグループ	経時的深度インタビュー
分野	調査方法論	調査方法論
系統	Process / pipeline	Process / pipeline
提唱年	1940s (focus groups); longitudinal variant refined 1980s–1990s	1990s–2000s (as a formalised qualitative method)
提唱者	Adapted from Robert K. Merton's focused interview tradition; longitudinal design developed in social and health sciences	Rooted in qualitative longitudinal research traditions; systematised by Johnny Saldana
種類	Qualitative longitudinal data collection	Qualitative longitudinal data collection technique
原典	Morgan, D. L. (1997). Focus Groups as Qualitative Research (2nd ed.). Sage Publications. ISBN: 978-0761903437	Saldana, J. (2003). Longitudinal Qualitative Research: Analyzing Change Through Time. AltaMira Press. ISBN: 978-0759103917
別名	repeated focus group, panel focus group, longitudinal FG, follow-up focus group	repeated in-depth interview, longitudinal qualitative interview, panel qualitative interview, longitudinal IDI
関連	5	5
概要	A longitudinal focus group convenes the same group of participants in multiple sessions over an extended period — weeks, months, or years — to trace how their attitudes, experiences, or interpretations evolve in response to changing circumstances. Unlike a single focus group snapshot, the repeated-contact design captures the dynamics of opinion and meaning-making across time, making it particularly valuable in health, policy, and social research where change is the phenomenon of interest.	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.