Answered By: Steven Profit
Last Updated: Mar 17, 2016     Views: 22

See these definitions from the Oxford Dictionary of Social Sciences:

With regard to any study or analysis, validity refers to the degree to which the analysis is properly conceived to address the subject of study. Validity is therefore different from accuracy or reliability: studies may be flawlessly conducted (accurate) and results may be repeatable (reliable), but the methods may nonetheless be inappropriate for achieving the desired results. An adequate measurement must be both reliable and valid.

The degree to which a research technique or experiment yields the same results over repeated attempts and by different researchers. Reliability is distinct from validity, which concerns whether a technique is an appropriate measure of the phenomenon in question.