A statistical technique used to obtain samples from a given population, whereby every unit in the population has a known, non-zero probability of being selected for inclusion in the sample. The conclusions from this type of sample can then be projected, within statistical limits of error, to the wider population. See also population, sample.
Random Sampling - A sampling method in which all elements in the population have an equal chance of being selected. Random samples have important properties that are necessary in many statistical tests. Stratified Sampling - participants are selected at random from mutually exclusive subgroups, for example drawing a random sample based on a personal characteristic such as age group, ethnic group or sex. Stratified Sampling helps ensure that subgroups are adequately represented in the study.
Also known as “random sampling.” Choosing people to be studied, in such a way that each person (or thing, place, etc.) in the total pool has an equal chance of being chosen.