Non-probability sampling refers to a sampling technique in which every member of the population does not have a known or equal chance of being selected. In this method, the researcher selects units based on convenience, judgement, accessibility, or specific characteristics. Unlike probability sampling, non-probability sampling does not depend on random selection. It is particularly useful in managerial applications when managers need quick information, when a complete sampling frame is unavailable, or when exploratory research is being conducted. One important method is convenience sampling. In this approach, the researcher selects respondents who are easily accessible and willing to participate. For example, a retail manager may collect opinions from customers available in the store at a particular time. This method is simple, economical, and less time-consuming. However, the sample may not adequately represent the entire population, leading to sampling bias. Judgement or purposive sampling involves selecting respondents according to the researcher's judgement about who can provide relevant and useful information. For example, a company studying leadership practices may deliberately select experienced managers from different departments. This method is useful when specialized knowledge is required, but the quality of the sample depends heavily on the researcher's judgement. Quota sampling is another non-probability method.