Sampling is the process of selecting a subset of individuals, events, or items from a larger population in order to study and draw conclusions about that population. It is a fundamental technique in research and statistics, used when studying the entire population is impractical, costly, or impossible.
A properly selected sample should be representative of the overall population, meaning it reflects the key characteristics of the larger group. When done correctly, the findings from the sample can be generalized with a certain degree of confidence to the broader population.
There are two major types of sampling:
- Probability sampling, where each member of the population has a known and equal chance of being selected (e.g., random sampling, stratified sampling).
- Non-probability sampling, where selection is based on subjective criteria (e.g., convenience or purposive sampling), is often used in exploratory research.
However, sampling can also be deliberately or unintentionally biased. If the sample is skewed, such as selecting only individuals with a particular opinion or background, it can distort the results and misrepresent the broader population. Therefore, transparency in the sampling method and its limitations is crucial for the validity of any research.