A group of persons are selected from a population in such a way that each individual has an equal chance of being chosen In addition, the selection of one person does not influence the chances of other people being selected
A sample in which all members of the target population have an equal and independent chance of being selected for the study; also known as a probability sample
In statistical terms a random sample is a set of items that have been drawn from a population in such a way that each time an item was selected, every item in the population had an equal opportunity to appear in the sample
A sample of a population that has the property that each item has an equal chance of being selected, and in which the chance of one item being selected does not affect the selection of any other item Random samples are often used to ensure that the sample is representative of the population Sometimes a sample that is not totally random but distributed uniformly with respect to nuisance parameters has desirable properties