Framework for an investigation of the methodological rigour of case studies40
| Internal validity | Construct validity | External validity | Reliability |
| Research framework explicitly derived from literature (diagram or explicit description of causal relationships) | Data triangulation (archival data; interview data; participatory observation; direct observation) | Cross-case analysis (either multiple case studies or nested cases within one organisation) | Case study protocol (how was case study conducted) |
| Pattern matching | Review of transcripts and drafts by peers | Rationale for case study selection (and why appropriate in view of research questions) | Case study database (with all available documents, interviews transcripts, etc) |
| Theory triangulation (different theoretical lenses or bodies of research used as research framework or for interpretation) | Review of transcripts and drafts by key informants | Details on case study contexts | Organisation's actual name provided explicitly in the report |
| Clear chain of evidence | |||
| Clear explanation of data-collection circumstances | |||
| Clear explanation of data analysis procedures |