Psychology -> Participant selection: random and stratified sampling
Participant selection: random and stratified sampling
Ensures that subject have as equal opportunity to be chosen as participants in the experiment
Usually yields a fairly representative result
Represents the general population on a certain characteristic
Prevents biases in the sample
Enables the researcher to generalise the findings to the wider population
Participant selection involves the way in which potential subjects are chosen to participate in psychological research.
This involves the selection of subjects in such a way, that each has an equal opportunity to be chosen as a participant in the experiment. A number of methods can be chosen such as:
- picking names out of a hat
- choosing every third person on an alphabetical list
If the sample is large enough, random sampling usually yields a fairly representative result.
In some experiments, the sample needs to be chosen to represent the general population on a certain characteristic, e.g. gender or age. Therefore, the researcher makes sure that the proportion of people in the sample with the particular characteristic is the same as the proportion of people in the general population with that characteristic. When subjects within each stratum are selected in a random way, it is called a stratified random sample. This method prevents biases in the sample and enables the researcher to generalise the findings to the wider population.