Sampling

Question 1

What is a population?

Answer 1

A whole set of items that are of interest

Question 2

What is a sample?

Answer 2

A selection of observations taken from a subset of a population, used to find out more information about the population as a whole

Question 3

State an advantage and disadvantage of a sample

Answer 3

Advantages
- less time consuming and cheaper
- fewer people have to respond
- Less data needs to be processed

Disadvantages
- data may not be as accurate
- sample may not be large enough to give information about small subgroups of the population

Question 4

State an advantage and disadvantage of a census

Answer 4

Advantages
- results should be completely accurate

Disadvantages
- time consuming and expensive
- hard to process large quantities of data

Question 5

What is a sampling unit?

Answer 5

An individual unit of a population

Question 6

State ab advantage and disadvantage of systematic sampling

Answer 6

Adv
- simple and quick to use
- suitable for large samples

Disadv
- sampling frame is needed
- if there is a periodic trait in the population the sample may not be representative

Question 7

Define stratified sampling

Answer 7

The population is divided into mutually exclusive strata and a random sample is taken from each