Non-probability sampling is a sampling technique in which not all members of a population have a known or equal chance of being selected. This method relies on the judgment of the researcher rather than random selection and is often used in exploratory research where representativeness is not the primary concern.
Examples include convenience sampling, purposive sampling, quota sampling, and snowball sampling. These methods are typically faster, easier, and more cost-effective than probability-based approaches, but they carry a higher risk of bias and limit the generalizability of the results.
Non-probability sampling is useful when time, access, or resources are limited, or when the research aims to gain in-depth insights rather than statistically valid conclusions.