Which term refers to a procedure where every member of the population has an equal chance of being selected?

Random sampling is the procedure that ensures every member of the population has an equal chance of being selected. This method is fundamental in research because it minimizes selection bias and allows the findings to be more generalizable to the larger population. By using random sampling, researchers can obtain a representative sample, which enhances the validity of their conclusions about the population being studied.

In contrast, systematic sampling involves selecting individuals based on a predetermined system or pattern, which does not guarantee equal chances for all participants. Volunteer sampling relies on individuals self-selecting to participate, which can lead to a non-representative sample as it may attract a certain type of person. Cluster sampling involves dividing the population into groups (or clusters) and then randomly selecting entire clusters, which does not ensure that every individual has an equal chance of being chosen, as it might exclude individuals from non-selected clusters.