S2 January 2005 Q2
2.
(a) Explain what you understand by (i) a population and (ii) a sampling frame. (2)
The population and the sampling frame may not be the same.
(b) Explain why this might be the case. (1)
(c) Give an example, justifying your choices, to illustrate when you might use
(i) a census,
(ii) a sample. (4)
| Scheme | Marks |
|---|---|
| (i) A collection of individuals or items | B1 |
| (ii) A list of all sampling units in the population | B1 |
| (2) |
| Scheme | Marks |
|---|---|
| Not always possible to keep this list up to date | B1 |
| (1) |
| Scheme | Marks |
|---|---|
| (i) e.g. Pupils in year 12 – small easily listed population | B1 |
| Population known & easily accessed | B1 |
| (ii) Students in a University – Large not easily listed population | B1 |
| Population known but too time consuming/expensive to interview all of them. | B1 |
| (4) | |
| (7 marks) |
Notes
SR (i) Definition of census by example B1
(ii) Definition of sample by example B1