Validity is a criterion for the quality of a scientific analysis and its findings. An analysis is valid, if it measured what it was supposed to measure, i.e. if the ascertained data truly answer the questions that were to be analyzed. When measuring instruments repeatedly come to the same accurate but false result, they can be considered reliable but not valid.
Please note that the definitions in our statistics encyclopedia are simplified explanations of terms. Our goal is to make the definitions accessible for a broad audience; thus it is possible that some definitions do not adhere entirely to scientific standards.