Although random sampling is generally the preferred survey method, few people doing surveys use it because of prohibitive costs; i.e., the method requires numbering each member of the survey population, whereas nonrandom sampling involves taking every nth member. Findings indicate that as long as the attribute being sampled is randomly distributed among the population, the two methods give essentially the same results. If the attribute is not randomly distributed, the two methods give radically different results. In some instances the nonrandom methods yield much better inferences about the population; in other instances, its inferences are much worse. The reasons for this phenomenon are discussed.
This report is part of the RAND Corporation Paper series. The paper was a product of the RAND Corporation from 1948 to 2003 that captured speeches, memorials, and derivative research, usually prepared on authors' own time and meant to be the scholarly or scientific contribution of individual authors to their professional fields. Papers were less formal than reports and did not require rigorous peer review.
This document and trademark(s) contained herein are protected by law. This representation of RAND intellectual property is provided for noncommercial use only. Unauthorized posting of this publication online is prohibited; linking directly to this product page is encouraged. Permission is required from RAND to reproduce, or reuse in another form, any of its research documents for commercial purposes. For information on reprint and reuse permissions, please visit www.rand.org/pubs/permissions.
The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.