Sampling Techniques Flashcards
What is random sampling
Every member of target population has an equal chance of being selected for the sample
Advantages of random sampling
It is unlikely that the sample will be biased, as the sampler has no control over who is in the sample.
It is possible to choose a specific subgroup in target population first.
Disadvantages of random sampling
random sampling can take a long time - target population can be large.
Often not random - all participants identified can be accessed and agree to participate.
What is stratified sampling
This sample is a proportional representation of the target population. The target population is broken down into smaller groups, for example gender or age. You then sample from those groups.
Advantages of stratified sampling
It can be very representative of the population if done correctly - whole population would be equally represented.
Specific subgroups can be chosen according to the variables considered to be important
Disadvantages of stratified sampling
It is very time consuming to do, and it also can be very difficult.
Decision on subgroups used can be biased
What is opportunity sampling
Sampler selects participants from whoever is available at the time
Advantages of opportunity sampling
Convenient and quick
Ethical
May be the only technique available if whole target population cannot be listed
Disadvantages of opportunity sampling
Less representative - taken from small section of populations
Participants may refuse participation so only based on those willing
What is volunteer sampling
Participants put themselves forward to be put in sample. Done mostly through advertising like Milgram used newspaper advertisements
Advantages of volunteer sampling
Participants will be very motivated
Easy to do
Gives variety to people who you would not normally have access to
Good way to get specialised group
Disadvantages of volunteer sampling
Volunteers will be similar - more willing and eager than wider population
