Multi-source In-depth Interview — Qualitative Data from Multiple Informant Groups
Also known as: multi-informant in-depth interview, multi-perspective qualitative interview, multiple-source IDI, multi-stakeholder in-depth interview
The multi-source in-depth interview is a qualitative data collection strategy in which extended, open-ended interviews are conducted with participants drawn from two or more distinct source groups — such as providers and clients, managers and staff, or experts and laypeople. Collecting data across diverse informant positions enriches description and enables the researcher to examine a phenomenon from multiple vantage points within a single study.
Key highlights
- Produces a richer, multi-angled account of a phenomenon than single-source designs.
- Enables systematic comparison across informant groups, revealing convergences and meaningful divergences.
- Strengthens credibility by documenting whether different actors corroborate or challenge each other's accounts.
- Particularly powerful for studying complex social processes involving multiple roles or levels.
- Purposive multi-source sampling makes theoretical sampling and maximum variation strategies straightforward to implement.
Intuition
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How it works
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When to use it
Use a multi-source in-depth interview design when the research question requires understanding a phenomenon as experienced by actors who occupy different roles, positions, or relationships to it — for instance, exploring how a social program is perceived by funders, implementers, and beneficiaries. It is particularly valuable in organizational, health services, education, and policy research where a single informant group would yield a systematically partial view. Do not use this design when the research question concerns only one clearly defined experiential group (a standard in-depth interview suffices), when resources do not permit adequate sampling across groups, or when the goal is theory-testing rather than exploratory description.
Strengths & limitations
- Produces a richer, multi-angled account of a phenomenon than single-source designs.
- Enables systematic comparison across informant groups, revealing convergences and meaningful divergences.
- Strengthens credibility by documenting whether different actors corroborate or challenge each other's accounts.
- Particularly powerful for studying complex social processes involving multiple roles or levels.
- Purposive multi-source sampling makes theoretical sampling and maximum variation strategies straightforward to implement.
- Requires substantially more time, resources, and access than single-source designs — each additional source group multiplies recruitment and interview burden.
- Cross-group analysis is more complex; the researcher must resist collapsing group-specific nuance into an artificially unified account.
- Balancing the depth of within-group analysis against the breadth of cross-source comparison is an ongoing methodological tension.
- Access to all relevant source groups is not always feasible, creating an incomplete picture if a key group is excluded.
Common pitfalls
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Frequently asked
How many participants do I need per source group?
There is no universal rule, but each source group should reach within-group thematic saturation independently — typically a minimum of five to eight participants per group. The total sample size thus multiplies with the number of groups. If resources are limited, prioritize depth within fewer groups over thin coverage across many.
Should I use the same interview guide for all groups?
No — the core research questions should be consistent, but the specific prompts and language must be adapted to each group's role and knowledge. Using an identical guide across very different groups risks producing data that is superficial or ill-fitted to each group's perspective.
How is this different from triangulation?
Multi-source in-depth interviews involve collecting the same data type (in-depth interviews) from different informant groups. Methodological triangulation involves using different data collection methods (e.g., interviews plus observation plus documents). Multi-source interview data can contribute to triangulation, but the strategy itself is not triangulation in the strict methodological sense.
What do I do when the accounts from different groups contradict each other?
Contradictions are data, not problems. Divergent accounts often reveal how different structural positions, interests, or experiences shape the way a phenomenon is understood. Document the divergence, analyze its pattern, and present it as a substantive finding rather than attempting to resolve it in favor of one group's account.
Can I combine this with online or telephone data collection?
Yes. The multi-source design refers to the sampling and analysis logic, not the medium of data collection. Interviews with different source groups can be conducted face-to-face, by telephone, or via video call, and different groups may be interviewed through different modes if that is most appropriate for each group.
Sources
- 1.Patton, M. Q. (2002). Qualitative Research and Evaluation Methods (3rd ed.). Sage Publications.ISBN 978-0761919711
- 2.Lincoln, Y. S., & Guba, E. G. (1985). Naturalistic Inquiry. Sage Publications.ISBN 978-0803924314
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Cite this page
ScholarGate. (2026, June 3). Multi-source In-depth Interview. ScholarGate. https://scholargate.app/survey-methodology/multi-source-in-depth-interview