Sampling Methods - Research Methods Flashcards
What is the target population?
the group of people that an investigation is concerned with or wishes to study and apply the findings to
what is a sample?
a small selection of people from the target population who are directly studied
what should a sample do?
represent the nature of the target population
what is a sampling method?
how the sample is chosen
what is a finite population?
the number of elements of the population is fixed, making it possible to enumerate/count it in totality
what is an infinite population?
the number of units in the population are uncountable, making it impossible to observe all the items.
what is an existent population?
the population which comprises of objects that exist in reality
what is a hypothetical/imaginary population?
the population exists hypothetically
what is random sampling?
everyone from the target population has an equal chance of being selected.
what is putting the names of everyone from the target population, then pulling out the number required an example of?
random sampling
what is opportunity sampling?
sampler selects participants from who is available at the time
what is stratified sampling?
the sample is a proportional representation of the target population
how is stratified sampling done?
the target population is categorised into subgroups - a random sample is then taken from each of these subgroups so that the size of each subgroup is representative of their size in the target population
what is volunteer sampling?
participants volunteer/put themselves forward. often involves advertising the study
what are the strengths of random sampling?
should represent the target population and eliminate sampling bias; should have strong external validity
what are the weaknesses of random sampling?
difficult to achieve (time, effort, money); not always possible; there is a chance too many people with certain characteristics may be selected or people may refuse to participate, meaning it is not representative
what are the strengths of opportunity sampling?
convenient, easy, quick
what are the weaknesses of opportunity sampling?
not every member of the target population may be available; certain types of people will be underrepresented in the study and findings will not be generalisable; if the study was replicated at different times/places it may be unreliable; risk of researcher bias
what are the strengths of stratified sampling?
useful if a small subgroup of target population may be missed by a random sampling method; the sample is completely representative
what are the strengths of stratified sampling?
useful if a small subgroup of target population may be missed by a random sampling method; the sample is completely representative
what are the weaknesses of stratified sampling?
difficult to achieve (time, effort, money); people can refuse to take part
what are the strengths of volunteer sampling?
most ethical; participants would be motivated; minimal effort from researcher
what are the weaknesses of volunteer sampling?
may be less representative - not everyone in the target population will see the advert and respond; volunteers usually have a more willing and eager to please personality or have the time and inclination to participate
