Field-based Multiple Case Study — Comparative Case Research
Field-based Multiple Case Study Research · Also known as: comparative case study, multi-site case study, cross-case study, multiple-case design
A field-based multiple case study is a qualitative research design in which the researcher conducts sustained, in-person investigation at two or more bounded real-world sites (the cases), gathering data through direct observation, interviews, and document analysis. By systematically comparing what is found across cases, the researcher can identify both shared patterns and meaningful differences, producing analytic conclusions that are more robust and transferable than a single-site study allows.
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When to use it
Use a field-based multiple case study when the research question asks 'how' or 'why' something happens in its real-world context, when the boundaries between the phenomenon and its context cannot be drawn clearly, and when you need richer transferability than a single case allows. It is especially suitable for studying organizational processes, policy implementation, community programs, or educational interventions across diverse settings. Plan for two to four cases as a minimum; more than ten becomes difficult to manage without a large research team. Do not use this design when a well-controlled experimental comparison is possible, when survey data would suffice, or when budget and time do not permit genuine, extended fieldwork at multiple sites.
Strengths & limitations
- Replication logic across cases makes findings more robust and analytic conclusions more credible than a single-case study.
- Rich, contextually grounded data from real field sites captures complexity that surveys and experiments often miss.
- Triangulation of observation, interviews, and documents within each case strengthens internal validity.
- Enables identification of both universal patterns and theoretically meaningful variation across contexts.
- Findings are transferable to settings that share key contextual features with the studied cases.
- Demanding in time, resources, and access: sustained fieldwork at multiple sites is expensive and logistically complex.
- Findings are analytically rather than statistically generalizable — they cannot be projected to a population using probability logic.
- Quality is heavily dependent on the researcher's fieldwork skills, reflexivity, and analytical rigor.
- Researcher presence in the field may influence the behavior of participants (reactivity).
- Managing and comparing large volumes of qualitative data from multiple sites requires systematic procedures and considerable analytic effort.
Frequently asked
How many cases do I need for a multiple case study?
Yin recommends a minimum of two cases — enough to begin cross-case comparison — but typically two to four cases are sufficient for theoretical replication purposes. More than six to eight cases without a large research team can overwhelm analytic capacity. The exact number should follow from the replication logic: add cases until the pattern is either confirmed or the theoretical contrast is established, not to hit an arbitrary target.
What makes this 'field-based' rather than just a multiple case study?
The field-based label signals that the researcher personally enters each site and collects primary data through direct observation and in-person interviews, not solely through secondary documents or remote interviews. Sustained presence in the field is what allows context-sensitive understanding that distinguishes this design from document analysis or survey research conducted about multiple sites.
How is multiple case study different from comparative research?
Comparative research often uses existing datasets, surveys, or secondary data to compare across units, and emphasizes explanation through variable analysis. Multiple case study relies on primary fieldwork within bounded real-world units and emphasizes thick description and context-sensitive interpretation. The multiple case study foregrounds the within-case narrative first, then uses replication logic for comparison; comparative research often begins with the comparison variables.
Can I use quantitative data within a field-based multiple case study?
Yes. Yin explicitly endorses mixed-evidence case studies. Quantitative data — attendance records, test scores, production figures — are legitimate sources of evidence within each case. The design remains qualitative in its overall logic (purposive case selection, replication rather than sampling, analytic rather than statistical generalization), but quantitative measures can strengthen and triangulate the within-case analysis.
How do I establish credibility in a multiple case study?
Four quality criteria from Yin's framework apply: construct validity (use multiple sources of evidence and a chain of evidence), internal validity (use analytic techniques such as pattern matching and explanation building), external validity (use replication logic across cases rather than sampling logic), and reliability (use a case study protocol and maintain a case study database that others could inspect).
Sources
- Yin, R. K. (2018). Case Study Research and Applications: Design and Methods (6th ed.). Sage. ISBN: 978-1506336169
- Stake, R. E. (2006). Multiple Case Study Analysis. Guilford Press. ISBN: 978-1593852481
How to cite this page
ScholarGate. (2026, June 3). Field-based Multiple Case Study Research. ScholarGate. https://scholargate.app/en/qualitative/field-based-multiple-case-study
Which method?
Set this method beside its closest kin and read them side by side — the library lays the books on the table; the choice is yours.
- Case StudyQualitative↔ compare
- EthnographyQualitative↔ compare
- Grounded TheoryQualitative Research↔ compare
- Narrative AnalysisQualitative↔ compare
- PhenomenologyQualitative↔ compare