Random sampling is a part of the sampling technique in which each sample has an equal probability of being chosen. A sample chosen randomly is meant to be an unbiased representation of the total population. If for some reasons, the sample does not represent the population, the variation is called a sampling error.

Stratified sampling refers to a type of sampling method . With stratified sampling, the researcher divides the population into separate groups, called strata. Then, a probability sample (often a simple random sample ) is drawn from each group.

Cluster sampling is a sampling plan used when mutually homogeneous yet internally heterogeneous groupings are evident in a statistical population. ... In this sampling plan, the total population is divided into these groups (known as clusters) and a simple random sample of the groups is selected.

Random samplingis a part of the sampling technique in which each sample has an equal probability of being chosen. A sample chosen randomly is meant to be an unbiased representation of the total population. If for some reasons, the sample does not represent the population, the variation is called a sampling error.Stratified samplingrefers to a type ofsamplingmethod . Withstratified sampling, the researcher divides the population into separate groups, called strata. Then, a probabilitysample(often a simple randomsample) is drawn from each group.Cluster samplingis asamplingplan used when mutually homogeneous yet internally heterogeneous groupings are evident in a statistical population. ... In thissamplingplan, the total population is divided into these groups (known asclusters) and a simple randomsampleof the groups is selected.