What is the sampling method that uses specific groups and does not select the whole population?

The sampling method that utilizes specific groups and does not involve selecting the entire population is purposive sampling. This technique is particularly useful when a researcher needs to build a sample that is representative of a particular characteristic or aspect of the population, focusing on certain groups that meet predefined criteria.

In purposive sampling, the researcher intentionally selects individuals based on attributes or qualities they possess that are pertinent to the study. This targeted approach allows for greater depth and relevance in qualitative research and is often employed in studies where the researcher seeks insights from specific segments of the population.

In contrast, cluster sampling involves dividing the population into separate groups (or clusters) and then randomly selecting some of those clusters to include all members from the chosen clusters in the sample. Stratified sampling requires the population to be divided into distinct subgroups, with samples taken from each subgroup to ensure representation across various segments. Quota sampling involves ensuring that certain characteristics or quotas within the sample are met, but it does not have the same intent or criteria specificity as purposive sampling.