Sampling

SAMPLING

Description

- Small group of people selected from a population.

Opportunity Sample - recruit those easily available.

Random Sample - use a random technique (e.g. lottery method or random number generator)

Stratified Sample - identify relevant subgroups then randomly select appropriate proportion from each subgroup.

Systematic Sample - select every nth person.

Volunteer Sample - people respond to an advertisement.

Evaluation

Opportunity Sample = easy because they are there, but biased.

Random Sample - unbiased, but takes time.

Stratified Sample - proportional, representative and unbiased, but time consuming.

Systematic Sample - unbiased, but not truly random.

Volunteer Sample - variety of participants, but volunteer bias.