The document discusses different sampling methods used in research. It defines sampling as making inferences about a whole population by examining a part of it. There are two main types of sampling: probability sampling, which uses random selection, and non-probability sampling, which does not. Some common probability sampling methods described are simple random sampling, systematic sampling, stratified sampling, and cluster sampling. The document also outlines some non-probability sampling techniques such as convenience sampling, judgement sampling, snowball sampling, and quota sampling.