Sampling Flashcards
What should you consider when sampling?
If Representative:
can be generalised to target market
Bias:
Did reasercher influence sample?
Time taken:
Is it quick or efficient?
Ease of Sampling:
Is ot easy to find them? Will they refuse?
Explain random sampling
= Each member has an equal chance eg out a hat
+ fair/ equal
+ can be representative
- difficult
- time comsuming
- unrepresentative (chance)
Explain systematic sampling
= every nth member of target pop is selected.
+ free from bias
+ fairly representative
- time consuming
- difficult
Explain stratified sampling
= subgroups in target pop identified and proportions to be representative are worked out.
+ free from researcher bias
+ representative (maths)
- difficult
- time comsuming
- selected PPTS nay refuse
= x / total × 100 = %
What is opportunity sampling?
= researcher takes chance to ask those willing and available
+ saves time
+ saves money
- not representative
- researcher bias
What is volunteer sampling
= advert put out, individuals select themselves to participate.
+ saves time
+ convenient
- volenteer bias
- not representative