Sampling Flashcards
What are the advantages of opportunity sampling?
Straight forward
Cheap
What are the disadvantages of opportunity sampling?
Can produce a biased sample
Participants may decline to take part and thus becomes more of a self selected study
What is volunteer sampling?
When participants volunteer or in response to an advert
What are the advantages of volunteer sampling?
Reach a wide variety
What are the disadvantages of volunteer sampling?
Usually biased as people are more likely to be more highly motivated and have extra time
What are the advantages of random sampling?
Unbiased yet representative sample
What are the disadvantages of random sampling?
Time consuming
Hard with large population
What is systematic sampling?
Researcher randomly selects first subjects then selects nth from list
What are the advantages of systematic sampling?
Degree of system or process to random selection
Population is evenly sampled
What are the disadvantages of systematic sampling?
Can interact with hidden trait of the population
What is stratified sampling?
Classify the population into categories and then choose sample consisting of same proportion as in population
What is an advantage of stratified sampling?
Should be representative of whole population
What is a disadvantage of stratified sampling?
Time consuming
What is opportunity sampling?
Taking samples from people who are available at the time of the study
