data collection

Simple Random

Each member of the population has an equal and known chance of being selected

Systematic Random Sample

After the size of the sample has been calculated, every nth item is selected from the population

Stratified Random Sample

A population is divided into subgroups based on some characteristic and random sampling is done within each subgroup to represent the whole population

Cluster Random Sample

Every member of the population is assigned to one group (cluster). The sample of the clusters is chosen and every member in that group is surveyed

Convenience Sample

A sample being drawn from that part of the population that is close to hand

Volunteer Sample

A sample made up of participants who have voluntarily chosen to participate as a part of the sample group