This document discusses different sampling methods used in research. It defines sampling as selecting a number of individuals from a larger group to represent it. Probability sampling methods like random sampling, stratified random sampling, cluster sampling, and systematic sampling aim to achieve a representative sample. Non-probability methods include convenience sampling, judgmental sampling, quota sampling, and snowball sampling, which do not require a complete sampling frame. Specific techniques like stratified random sampling divide a population into subgroups and randomly select from each, while cluster sampling selects intact groups.