手法を比較

	構造化面接	フォーカスグループリサーチ	詳細インタビュー
分野	調査方法論	質的手法	質的手法
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1940s–1950s	1940s (sociological origin); modern applied form from the 1980s–1990s	Mid-20th century (formalised in qualitative social research from the 1950s onward)
提唱者	Survey research tradition; formalized by Campbell, Katona, and Kahn in mid-20th century	Robert K. Merton (sociological precursor, 1940s); popularised in applied research by Richard A. Krueger	Rooted in sociological interviewing traditions; systematised by researchers including Steinar Kvale and Herbert J. Rubin
種類	Quantitative / mixed data collection technique	Qualitative data collection method	Qualitative research method
原典	Fontana, A., & Frey, J. H. (2000). The interview: From structured questions to negotiated text. In N. K. Denzin & Y. S. Lincoln (Eds.), Handbook of Qualitative Research (2nd ed., pp. 645–672). Sage.	Krueger, R.A. & Casey, M.A. (2014). Focus Groups: A Practical Guide for Applied Research (5th ed.). Sage. ISBN: 978-1483365244	Kvale, S. (1996). InterViews: An Introduction to Qualitative Research Interviewing. Sage. ISBN: 978-0803958203
別名	standardized interview, formal interview, schedule-based interview, fixed-format interview	focus group discussion, FGD, group interview, Odak Grup Araştırması	IDI, semi-structured interview, unstructured interview, qualitative interview
関連	4	6	6
概要	A structured interview is a data collection technique in which every participant is asked exactly the same pre-specified questions in the same order, using standardized wording. Because the interview schedule is fixed, responses across participants are directly comparable, enabling quantitative aggregation and statistical analysis. It sits at the most standardized end of the interview continuum, between the self-administered questionnaire and the semi-structured interview.	Focus group research is a qualitative data-collection method in which a trained moderator guides structured discussions with homogeneous groups of six to ten participants to explore ideas, attitudes, and perceptions on a defined topic. Developed from sociological roots in the 1940s and systematised for applied research by Krueger and Casey, the method leverages group interaction as a data source — revealing not just what people think, but how they negotiate and articulate views in a social setting.	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.