• Validity. The measures of performance should also be valid. In this context, validity refers to the fact that the measures include all relevant performance facets and do not include irrelevant performance facets. In other words, measures are relevant (i.e., include all critical performance facets), not deficient (i.e., do not leave any important aspects out), and are not contaminated (i.e., do not include factors outside of the control of the employee or factors unrelated to performance).