Sampling Methods Flashcards
What is random sampling?
Everyone in the target population have an equal chance of being selected.
Strengths of random sampling
More generalisable - low bias
Weaknesses of random sampling
Can’t 100% certain that the sample is representative of the target population.
Difficult to include all the population for sampling - some may be unavailable or data protection means they can’t be accessed
What is Stratified sampling?
All the relevant groups within the target population are proportionally represented within the sample.
Strengths of Stratified sampling
All relevant groups will have some representation
Limits the amount of ppts needed - keep costs low
Weaknesses of Stratified sampling
It is difficult to know how many of each group is need to represent the T.P accurately - some may be over or under represented
What is Opportunity sampling?
Researcher takes advantage of whoever’s available at the time/place of testing.
Strengths of Opportunity sampling
More ethical - can see if people are willing
Easy and faster
Weaknesses of Opportunity sampling
May not be representative of the target population
Researcher bias - pick people who know/ are comfortable talking to
What is Volunteer sampling?
Researcher puts out an advert and people that want to participate come forward.
Strengths of Volunteer sampling
Ethical
Ppts more likely to comply and follow instructions - less issues with non-compliance
Weaknesses of Volunteer sampling
Bias - as volunteers are in the minority (most people wouldn’t volunteer)
May take a long time to get enough ppts
