Sampling
Bias
A systematic distortion
Generalisation
Applying the findings of a particular study to the target population
Opportunity sampling
A sample of participants produced by selecting people who are most easily available at the time of the study
Quota sampling
Similar to a stratified sample except participants are not selected from strata using a random sampling technique
Random sampling
A sample of participants produced by using a random technique so that every member of the target population being tested has an equal chance of being selected
Sampling
The selection of participants from the sampling frame with the aim of producing a representive selection of people from that group
Sampling frame
The source material from which a sample is drawn
Self-selected sampling
A sample of participants that relies solely on volunteers to make up the sample.
Snowball sample
Relies on referrals from initial participants to generate additional participants
Stratified sampling
A sample of participants produced by identifying subgroups according to their frequency in the target population. Participants are then selected randomly from the subgroups.
Systematic sampling
A sample obtained by selecting every nth person (where n is any number). This can be a random sample if the first person is selected using a random method; you then select every nth after that
Target population
The group of people that the researcher is interested in. The group of people from whom a sample is drawn. The group of people about whom generalisations can be made