Sampling

Sampling involves any procedure that draws conclusions based on measurements of a portion of the population. In other words, a sample is a subset from a larger population. If certain statistical procedures are followed, a researcher need not select every item in a population because the results of a good sample should have the same characteristics as the population as a whole. Of course, when errors are made, samples do not give reliable estimates of the population. (Zikmud; 2009; 68)

Sampling is defined in terms of the population being studied. A population (universe) is any complete group—for example, of people, sales territories, stores, or college students that shares some common set of characteristics. The term population element refers to an individual member of the population. (Zikmud; 2009; 387)

Referensi:

Zikmund William,  Babin Barry J, Carr John C, Griffin Mitch; 2009. Business Research Method, Eight Edition.