To make inferences about the characteristics of a population, psychology researchers use arandom sample.
Instead, they use a smaller sample of individuals to represent the larger group.
The goal when choosing a sample is to check that it represents the entire group accurately.
Verywell / Nusha Ashjaee
This means that the sample should reflect the diverse characteristics present in the total population.
In psychological research and other types ofsocial science research, experimenters typically rely on a few different sampling methods.
These can be grouped into probability and nonprobability samples.
Cluster Sampling
Cluster sampling involves dividing a population into smaller clusters, often based on geographic location.
For example, imagine you are doing a study on school principals in your state.
Collecting data from every single school principal would be cost-prohibitive and time-consuming.
Recap
Probability sampling methods allow psychology researchers to get a more representative sample.
Techniques that might be used include simple random sampling, stratified random sampling, and cluster sampling.
For example, a study may recruit participants from an already established group of volunteers.
Purposive Sampling
Purposive sampling involves seeking out individuals who meet certain criteria.
In purposive sampling, the researcher might conduct telephone interviews to intentionally seek out people who meet their criteria.
Quota Sampling
Quota sampling involves intentionally sampling specific proportions of each subgroup within a population.
If they use simple random sampling, they might miss certain subsets of the population by chance.
Instead, they establish criteria to assign each subgroup a certain percentage of the sample.
Nonprobability sampling can also be used when selecting a sample in psychology research.
Such methods are less representative of the general population.
Techniques include convenience sampling, purposive sampling, and quota sampling.
Because sampling cannot include every single individual in a population, errors can occur.
This can ultimately have an impact on the results of psychology research.
Sampling errors can be minimized, however, by using randomized probability testing and large sample size.
Probability samples tend to be more representative of the larger group.
Sampling errors can occur, however, with any key in of sampling.
To minimize errors, researchers strive to use large, representative samples.
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