sampling techniques Flashcards
sample
the people the sociologists actually study in their research
sampling frame
a list of all the people in the population who are relevant to the particular topic being studied
random sampling
random sampling - purely random using eg random number generators
systematic sampling - where you select every nth name from a list
random sampling advantages
- ensures every individual has absolutely equal chance of being selected
- quick and easy to carry out
random sampling disadvantages
- could be unrepresentative eg by chance more males than females
- requires accurate, up-to-date and complete sampling frame
stratified random sampling
to stratify your sample so it represents the general population - you then draw randomly
stratified random sampling advantages
- ensures control of variables such as age and sex that are important to the research
- can increase precision and so improve representativeness of sample
stratified random sampling disadvantages
- complex and time-consuming to identity to strata and to sample various sub-groups
- sampling frame may not contain required info to split sample-population into groups
- your values and views on society may influence choice of stratification - bias
cluster sampling
the entire population is divided into groups (cluster) and a random sample of these clusters is selected
all observations in the selected clusters are included in the sample
cluster sampling advantages
- useful if a complete list of the population is unavailable, but you can get a complete list of groups or clusters of the population
- cheaper than random sample if list of subjects is widely scattered
cluster sampling disadvantages
could be unrepresentative as clusters may not accurately reflect the general population
quota-sampling - non
find a specific number of a particular types of person, once quota filled they stop
often in market research
quota sampling advantages
- can control variables without a sampling frame
- cheap and quick
quota sampling disadvantages
- not random
- may have to ask personal questions to discover whether respondent matches the necessary criteria of study
- not representative as quota sampling
snowball sampling - non
respondents recruit one individual who will then get people they know to participate in the study - these people will then get further participants
snowball sampling - advantages
- no sampling frame needed
- can allow access to sensitive, marginalised and secretive groups eg drug users
snowball sampling - disadvantages
- not representative - network of contracts likely to be of similar backgrounds
- may run out of participants making it difficult to generalise
- self-selected - those who volunteer may be different from those who refuse
targeted sampling - non
where you target specific individuals you wich to sample - this method is more common in social policy research than in sociology
targeted sampling advantages
you will hopefully get access to exactly the people you wish to study
targeted sampling disadvantages
not representative of wider population
small sample sizes
volunteer sample - non
people volunteer to take part in the study, normally by replying to adverts, leaflets and posters
volunteer sample advantages
- no need for sampling frame
- advertise in areas where people who are appropriate for the study may be
- can allow access to sensitive, marginalised and secretive groups
volunteer sample - disadvantages
- unlikely to be representative of the general population
- may not get a large sample depending on how people volunteer
opportunity sampling - non
you take a sample who are quickly and conveniently available
opportunity sample advantages
can gather data very quickly if you wish to get a feel about a particular topic
opportunity sampling disadvantages
very unlikely to be remotely representative
