Measurements not only provide better information about candidates, they provide more information about candidates. However, before we can conclude our evaluation of the two methods, we must also consider the concept of validity. Validity and Screening Validity refers to the legitimacy of using a measurement for a specific purpose. A given measurement may be a reliable indicator of math ability but have no validity in predicting an individual's life span expectancy. However, measurement theory clearly indicates that there can be no hope of validity if there is no reliability.
Reliability sets the upper limit for validity.
In screening candidates, validity refers to the accuracy in predicting a candidate's likely success in the remaining phases of the selection process and on the job performance. According to professional standards, employee selection procedures need to be validated. Content validity requires demonstrating that a screening item has a clear and logical relationship to the content of the job. The screening item should be representative of the knowledge, behavior, or motivations that have been shown to comprise the requirements of the job. There is typically no statistic that represents validity in a content validity approach.