sampling Flashcards
sampling
A process whereby a researcher chooses their sample.
sample
Small group chosen from the target population./ A smaller sub-group to drawn from the wider group that we are interested in.
population
The group of people you want to make assumptions about.
target population
The specific people the researcher aims to study.
sampling frame
group of people from which you will draw your sample ( not as large as population)
what is the purpose of sampling?
The basic purpose of sampling is to ensure that those people that are chosen to include in the study are representative or typical of the research population, including all the people we have not been able to include within the study.
what is the sampling frame?
A list of all members of the population who we are interested in studying → important that the list is as complete and accurate as possible
What is random sampling?
Simplest technique / Names are selected purely by chance
* A large enough random sample should be able to reflect the characteristics of the whole population.
Quasi - random / systematic sampling
Where every nth person in the sampling frame is selected → Wilmott
stratified sampling
- Researcher first stratifies ( breaks down) the population in the frame by age, class, gender → sample is then created with the same proportions
- The population is stratified as above and then each interviewer is given the quota of say, 20 females and 20 males ; which they have to fill with respondents who fit these characteristics → the interviewer keeps at this until it is filled.
practical reasons why not able to create representative sample
- Social characteristics of the research population such as age,gender and class
( may not be known)→ then be impossible to create a sample that was an exact cross- section of the research population. - May be impossible to create a sampling frame for that particular research population → for example not all criminals are convicted so not all names are available to select a sample
- Potential respondents may refuse to participate.
what is snowball sampling?
- involves collecting a sample by contacting a number of key individuals, who are asked to suggest others who might be interviewed.
- And so on therefore adding to the sample until enough data has been collected
Although not representative → can be a useful way to contact a sample of people who might otherwise be difficult to find or persuade to take part e.g criminals.