2.2 - Populations, Samples & Sampling Techniques
The concepts of target population and sample in research
In research, the target population refers to the group of people the researcher is interested in, and the sample is drawn from this population.
Random sampling and its characteristics
Random sampling is the selecting of participants in a way that each member of the target population has an equal chance of being chosen. There is no bias in who is chosen so the sample is likely to be representative. There is, however, the chance of obtaining a freak sample as the researcher has no control over who will be selected.
Snowball sampling and its applications
Snowball sampling relies on initial participants recruiting others to generate additional participants. The sample is unlikely to be representative, though it is an easy way of gathering a sample if specific sample features are required, for example gamblers, soccer players, health practitioners.
Opportunity sampling and its practicality
Opportunity sampling is produced by selecting people who are most easily available at the time of the study. The sample is unlikely to be representative, though this is a quick and easy way of gathering a sample as the researcher just has to ask people who are around at the time of the investigation to be the participants.
Self-selected sampling and participant cooperation
Self-selected sampling is produced by asking people to volunteer to take part in a study. The study is unlikely to be representative, though participants who volunteer will usually be willing and co-operative so perform to the best of their ability.