sampling Flashcards
what does it mean when a population has validity?
the results generalise to other people.
the more a sample looks like the original population…..
the more representative we say it is
when it is impossible for a researcher to test everyone in the population what do they do?
so they pick a sample
what is a better sample
representative of the population
what are the five types of sampling?
volunteer sampling opportunity sampling systematic sampling random sampling stratified sampling
what is sampling?
when researchers pick a sample of the population
what is volunteer sampling
when the researcher posts an advertisement and people apply to be participants in the study
advantage of volunteer sampling?
it is easy and can reach lots of people
what is the limitation of volunteer sampling ?
the sample will not be very representative of the population
what is opportunity sampling?
when a researcher approaches members of the population who are willing and available to be participants
what is an advantage of opportunity sampling?
it is a quick and easy way to sample participants
what is a limitation of opportunity sampling?
the sample won’t be representative of the population
why is volunteer sampling easy?
because all you have to do is put an ad up and wait
why is opportunity sampling easy?
because all you have to do is go and talk to people
why is volunteer sampling unrepresentative?
only certain types of people will volunteer
why is opportunity sampling unrepresentative?
only get participants who are willing and available at the time
why might opportunity sampling lead to an unrepresentative sample
No matter where or when you do opportunity sampling, some members of the population are more likely to be there and more likely to be willing and available.
what is a better sample?
representative of the whole population
what is systematic sampling ?
when researcher’s pick every nth person from the entire population
what is an advantage of systematic sampling?
that it will often lead to a more representative sample than volunteer or opportunity sampling. this is because it involves sampling from the entire or whole population
what is an limitation of systematic sampling?
it is difficult because the researcher has to obtain a list of the whole population
a second con is that there is a pattern in how the data is listed, the sample may not be representative of the whole population
what is random sampling?
picking randomly from a list of the entire population, so that everyone has a equal chance of being a participant
what is an advantage of random sampling ?
representative because every member of the population has an equal chance of being included
what is a limitation of random sampling
it is more difficult because you need a list and and a way to randomise it
it still doesn’t guarantee that the sample will look like the population
