Sam pling Methods

Sampling Method
Useful for
Not useful for

 Stratified sampling

Selecting a smaller sample that is fully representative of the wider population

A very small sample group when the numbers would be so small that they are not statistically valid

Quota sampling

Selecting a smaller sample that is fully representative of the wider population

Can sometimes reinforce existing opinions
Selecting a sample in a hard to reach community where you don’t have existing contacts

Purposive/snowball sampling

Finding out who has information when you don’t already know
Getting well-informed responses from people with expertise

Accurate representation of the whole population
Can sometimes reinforce existing opinions

Cluster sampling

Selecting a manageable sample from a very large population

Accurate representation of the whole population

Fig. 6