Multistage sampling
For example, select regions, then branches within those regions, then invoices within selected branches. The design can be practical for geographically dispersed populations, but each stage affects selection probabilities and uncertainty. Document the frame, selection method and any weights used for the final estimates.
Worked example
A team randomly selects regions, then branches in those regions, then invoices in each selected branch. The result is a multistage sample.
Common mistake
Describing any large sample as multistage, or ignoring unequal selection probabilities introduced at earlier stages.
Where it appears in your exams
| Qualification | Exam | Relationship | Period |
|---|---|---|---|
| ACCA | MA | Direct | September 2026–June 2027 |
| FIA | FMA | Direct | September 2026–June 2027 |