Quant #23: Sampling Methods

In quantitative research, data must be collected from the population. However, as is often the case, it is difficult to obtain information from everyone in the population. The common approach is to gather information from a small portion of the population. This is portion is called the sample. To be able to make the right conclusion about the study, it is important to rely on the right methods to sample. Two types of sampling methods can be distinguished: probability sampling and non-probability sampling.

In probability sampling, every member of the population has a chance of being selected. Probability sampling allows for results that are representative of the whole population. Probability sampling is also known as random sampling. Types of probability sampling include simple random sampling, systematic random sampling, stratified random sampling, and cluster random sampling.

Non-random sampling refers to a sampling in which members of the population are selected based on non-random criteria. In this sampling, not every member of the population has a chance of being selected. Types of non-random sampling include convenience sampling, voluntary response sampling, purposive sampling, and snowball sampling.