Purposive Sampling
A non-probability sampling method where the researcher relies on their own judgment when choosing members of population to participate.
What is Purposive Sampling?
Also known as judgmental or subjective sampling, purposive sampling deliberately selects participants based on the qualities they possess. Researchers decide what needs to be known and sets out to find people who can and are willing to provide the information by virtue of knowledge or experience.
Why Purposive Sampling Matters
It is crucial in qualitative research where the goal is to deeply understand specific phenomena from key informants rather than to estimate population parameters.
Example
A researcher studying the integration of a specific experimental pedagogy selects exactly five teachers who have used the method for over ten years to interview.
Common Mistakes
- Using it to estimate population frequencies, which it cannot do.
- Failing to clearly articulate the criteria used to select participants, compromising transparency.