sampling Flashcards
what is a volunteer sample
where participants pick themselves through newspaper adverts, noticeboards or online
what is a weakness of volunteer sampling
may not provide a representative sample and could be biased as those who volunteer are likely to share similar characteristics resulting in volunteer bias
what is a strength of volunteer sampling
a quick and easy way of choosing participants, relatively cheap
what is opportunity sampling
uses people who are available at the time the study is carried out
e.g recruiting students from a uni or school
what is a weakness of opportunity sampling - characteristics
may not provide a representative sample and could be biased because those who are approached are likely to share similar characteristics
what is a weakness of opportunity sampling - bias
the researcher has total control over who is asked to take part in the study which can create researcher bias. this can impact the study and its findings/conclusions
what is a strength of opportunity sampling
quick cheap easy way of choosing participants
what is random sampling
when every person in the target population has an equal chance of being selected, the sample should represent the target population and eliminate bias
what are the weaknesses of random sampling
small minority groups can distort the results
it is impossible for it to be truly random
it is expensive and time consuming
what is the strength of random sampling
it is possible to have a representative sample as each member of the target population has an equal chance of being selected
it is also unbiased
what is systematic sampling
a system used to select participants which should provide a more representative sample using every nth person in a list
what are 2 weaknesses of systematic sampling
it is difficult to achieve due to time and money
not truly random as list could be biased if it is arranged in a certain way
what is a strength of systematic sampling
unbiased way of gaining a representative sample
what is stratified sampling
when you identify the subgroups (known as strata) and select participants in proportion to their frequency
what is a weakness of stratified sampling
extremely time consuming to gather and difficult, you must also be very careful that the strata is accurate or it will be biased
