sampling Flashcards
random sample
all members of the target population have an equal chance of being selected
e.g name generator, random number generator
strength of random sampling
unbiased
extraneous and confounding variables should be equally divided
limitation of random sampling
difficult and time-consuming to conduct, an entire list of the target population will be hard to obtain
could end up with a sample that is still unrepresentative
systematic sample
when every nth member of the target population is selected
strength of systematic sampling
objective
the researcher will have no influence over who is chosen (reduces bias)
limitation of systematic sampling
method is time-consuming
stratified sample
the composition of the sample reflects the proportions of people in certain subgroups within the target population
strength of stratified sampling
produces a representative sample because it is designed to accurately reflect the population (more generalisable)
limitation of stratified sampling
the identified subgroups cannot reflect all the ways that people are different
opportunity sample
researcher simply takes the chance to ask whoever is around at the time of their study
strength of opportunity sampling
convenient - much less costly in terms of time and money
limitation of opportunity sampling
sample is unrepresentative of the target population as it is drawn from a specific area
researcher has complete control over the selection of participants
volunteer sample
pps select themselves to be part of the sample
strength of volunteer sampling
requires minimal input from the researcher, less time-consuming and researcher ends up with pps who are likely o be more engaged with the study
limitation of volunteer sampling
volunteer bias - asking for volunteers may attract a certain ‘profile’ of person
