Systematic sampling
For example, choose every tenth item from an ordered list after a suitable starting position. It is straightforward to administer, but an ordering pattern that repeats at the same interval can bias the sample. Examine the sampling frame and document the start and interval.
Worked example
From an invoice list, select every 20th invoice after a randomly chosen start between 1 and 20. The team checks that the order has no repeating pattern linked to that interval.
Common mistake
Assuming every-tenth selection is automatically representative when the list has a ten-item cycle.
Where it appears in your exams
| Qualification | Exam | Relationship | Period |
|---|---|---|---|
| ACCA | MA | Direct | September 2026–June 2027 |
| FIA | FMA | Direct | September 2026–June 2027 |