Confronta i metodi

	Intervista approfondita	Intervista Semistrutturata	Indagine
Campo	Qualitativo	Qualitativo	Metodologia delle indagini
Famiglia	Process / pipeline	Process / pipeline	Process / pipeline
Anno di origine	Mid-20th century (formalised in qualitative social research from the 1950s onward)	1946 (Merton & Kendall); codified as a standard method through the 1980s–1990s	Late 19th century; systematic social-science use from 1940s
Ideatore	Rooted in sociological interviewing traditions; systematised by researchers including Steinar Kvale and Herbert J. Rubin	Robert K. Merton and Patricia Kendall (focused interview, 1946); further systematised by Steinar Kvale	Francis Galton, Charles Booth, and early social statisticians; formalised by Paul Lazarsfeld in the 1940s
Tipo	Qualitative research method	Qualitative research method	Quantitative (primarily) or mixed-methods data-collection instrument
Fonte seminale	Kvale, S. (1996). InterViews: An Introduction to Qualitative Research Interviewing. Sage. ISBN: 978-0803958203	Kvale, S., & Brinkmann, S. (2009). InterViews: Learning the Craft of Qualitative Research Interviewing (2nd ed.). Sage. ISBN: 978-0761925422	Dillman, D. A., Smyth, J. D., & Christian, L. M. (2014). Internet, Phone, Mail, and Mixed-Mode Surveys: The Tailored Design Method (4th ed.). Wiley. ISBN: 978-1118456149
Alias	IDI, semi-structured interview, unstructured interview, qualitative interview	guided interview, semi-standardized interview, focused interview, SSI	questionnaire survey, survey research, self-report survey, questionnaire study
Correlati	6	6	6
Sintesi	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.	The semi-structured interview is a qualitative data-collection method in which the researcher prepares a set of key questions or topic areas in advance but remains free to probe, follow up, and reorder as the conversation evolves. Unlike structured interviews — which fix every question and sequence — or unstructured interviews — which are entirely open — the semi-structured format balances comparability across participants with the flexibility needed to capture the depth and nuance of individual perspectives. It is the most widely used interview format in social science, health, and education research.	A survey is a systematic data-collection method in which a standardised set of questions is posed to a sample of respondents to measure attitudes, behaviours, demographics, or other constructs. Surveys can be administered via paper, telephone, online platforms, or face-to-face. They are among the most widely used instruments in social, behavioural, health, and educational research because they can reach large, geographically dispersed samples at relatively low cost.