Methods-Sampling methods Flashcards
Define representative
If a sample is representative it characterises the target population
Define generalisability
This means the findings can be used to make general assumptions about different groups
Define validity
How well does something measure what it is supposed to measure
Define reliability
How repeatable is your method
What is random sampling? (simple sampling)
Every individual in the survey population has an equal chance of being picked out for investigation
What is the advantage of random sampling?
No bias
What is the disadvantage of random sampling?
Unrepresentative sample- too many people of one sex, age group, social class
What is systematic sampling?
Homes are selected from the sampling frame at regular intervals until the sample size is reduced
What is the advantage of systematic sampling?
-No bias
-Can be done with a computer so is quick
What is the disadvantage of systematic sampling?
-Unrepresentative as it depends on how the lsit is organised
What is stratified random sampling?
Attempting to avoid the possible errors caused by simple sampling, subdividing
What is the advantage of random sampling?
-More likely to be representative
-Quick as a computer can do it
What is the disadvantage of random sampling?
-Complex
-Could be unrepresentative as you could miss out a whole demographic
What is quota sampling?
People are selected who are in certain categories according to their proportion in the survey population
What is the advantage of quota sampling?
-Select a sample tailored to the study
-Quick
What is the disadvantage of quota sampling?
-Not representative as the interviewer could be biased
What is multistage or cluster sampling?
-Selecting a sample in various stages each time selecting a sample from the previous sample until the final sample is selected
What is the advantage of multistage or cluster sampling?
-Quick
-Easy
What is the disadvantge of multistage or cluster sampling?
-Not representative
What is snowball sampling?
-The researcher picks 1 or 2 people for a certain characteristic and then these people will find other people
What is an advantage of snowball sampling?
-Can be useful
What is the disadvantge of snowball sampling?
-Self-selecting could create bias
