Sampling Methods Flashcards
To be able to identify and describe different sampling methods, and describe advantages and disadvantages of each.
Simple Random Sample
Every person has an equal chance of being
selected.
This sample is usually done by giving every
member a number, then choosing these numbers
randomly.
Stratified Sample
The same proportion of people in different groups
are selected
(EG 20% chosen from each year group in a school)
Quota Sample
A particular characteristic (or quota) is chosen.
(EG people with blue eyes, 18-60 year olds, men only)
Systematic Sample
A person (or object) chosen at regular intervals
(EG every 10th person is selected from a register)
Cluster Sample
The population is split naturally into groups (or
clusters). A number of groups are selected and all
members of these groups sampled.
Opportunity Sample
Use the people (or objects) available at the time.
(EG ask the first 50 people you come across)
Judgement Sample
Use your judgement to select a representative
sample.
What to consider when choosing a sampling method?
- Will the sample be biased?
- Will the sample size be sensible?
- How quick and easy is it?
- How much will it cost?
