How we change what others think, feel, believe and do
Use when you are unable to access a wider population, for example due to time or cost constraints.
Do not worry too much about taking random samples of the population - just use people who are available. Use people in the street, people you know, people who work with you, customers and so on.
Do use as many people as possible to ensure results from a single test is not just a coincidence.
A group of students in a high school do a study about teacher attitudes. They interview teachers at the school, a couple of teachers in the family and few others who are known to their parents.
Convenience sampling generally assumes a homogeneous population, and that one person is pretty much like another. Whilst people are known to be different, the difference is assumed to be probabilistic - thus if 80% of a sample prefer coffee to tea, you might conclude that 80% of the population at large would choose coffee. In practice, your sample may be mostly middle class Parisians and the same test in London may well give a different result.
Many famous psychological experiments were done with available people. Most typically, experiments done in universities use students, simply because they are cheap, willing and available. This has caused significant debate about the validity of results.
Convenience sampling is also known as Opportunity Sampling, Accidental Sampling or Haphazard Sampling.
Convenience sampling is a non-probability sampling method.
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