Research methods - Sampling Techniques Flashcards
what is the population
the total set of all the cases that exist
why do researchers need to use sampling techniques
it is not possible to study the whole population directly, so researchers need to use sampling techniques to provide a sample of people who are representative of the target population
describe random sampling
a sample in which any member of the population has an equal chance of being selected
describe opportunity sampling
researchers take their sample from people that happen to be in the area and are willing and available to participate
describe volunteer sampling
participants sign up to be part of the research, usually responding to adverts. the researcher must include contact details
describe snowball sampling
a few potential participants are contacted and asked whether they know of anybody with the characteristics that you are looking for in your research. a snowball sample is generated from existing participants asking their colleagues, friends or family to participate
what are the strengths of random sampling
representative - every member has an equal chance of being selected
no researcher bias
what are the weaknesses of random sampling
time consuming
unlikely to be a true random sample (lack of information/access)
what are the strengths of opportunity sampling
quick and easy and inexpensive
what are the weaknesses of opportunity sampling
not very representative - lacks generalisability as people are all in the same area
researcher bias as researcher picks people themselves
inevitably biased due to sample being drawn from a small part of the target population
what are the strengths of volunteer sampling
lack of researcher bias as the researcher does not choose
convenient way to find willing and eager participants who are less likely to drop out
what are the weaknesses of volunteer sampling
not representative as volunteers are likely to share characteristics - volunteer bias
what are the strengths of snowball sampling
good for researching hard to reach groups e.g drug users
what are the weaknesses of snowball sampling
unlikely to be a good cross section from the population due to it being friends of friends -lack of diversity
