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.

This type of sampling results in every sampling unit in a finite population having a calculable and non-zero probability of being selected in the sample. This means that the chance of a unit being included in a sample can be calculated.

A sample selected by a random procedure that gives every member of the population to be sampled a known nonzero chance of selection. The probabilities of selection may or may not be equal.

Sampling in which every individual has a known probability of selection.

any sampling method where the probability of any population element's inclusion is known and is greater than zero.

A sampling technique that ensures that each element of the population has a fixed probabilistic chance of selection

A sampling strategy in which every unit has a known non-zero probability of inclusion in the sample.

Sampling techniques that do not use random selection

A method for drawing a sample from a population such that all possible samples have a known and specified probability of being drawn.

(Also referred to as "Random Sampling") A sampling procedure which gives each of the possible samples a fixed and determinate probability of selection or which gives each unit on a sampling frame a fixed and known chance of being included in the sample. Probability samples permit the calculation, from the sample data, of measures of reliability for the estimates.

A method of drawing a sample such that the probability of a particular individual being included in the sample is known or can be estimated with reasonable precision.