Nonprobability sampling means:

Nonprobability sampling refers to a method of selecting participants or units for a study in which the selection is not based on known probabilities. In this context, researchers often rely on their judgment or criteria for choosing who or what to include in the sample. This can involve selecting participants who meet certain characteristics or fit a specific demographic profile.

Using judgment in selection allows researchers to focus on specific populations or situations that are of particular interest to their study, rather than attempting to achieve a random sample. This approach is useful in exploratory research where insights are based on qualitative depth rather than statistical representation.

In contrast, methods that involve giving each unit a known probability of being selected or ensuring an equal chance for all units are characteristic of probability sampling. These methods are used to ensure a representative sample that can facilitate generalizable conclusions across the entire population. Therefore, the reliance on researcher judgment in nonprobability sampling sets it apart from these more systematic approaches.