The document discusses different methods of sampling used in statistical analysis. It defines sampling as selecting a subset of a population to make inferences about the whole population. There are two main types of sampling: probability sampling, where every unit has a chance of selection, and non-probability sampling, where the probability of selection cannot be determined. Some examples of probability sampling methods provided are simple random sampling, stratified sampling, systematic sampling, and cluster sampling. Examples of non-probability sampling include judgment sampling, quota sampling, convenience sampling, purposive sampling, and snowball sampling.