Simultaneous validity is a parameter used in sociology, psychology and other psychometric or behavioral sciences. Simultaneous validity is demonstrated when a test correlates well with a measure that has previously been validated. The two measures can be for the same construct or for different constructs that are allegedly related.
For example, a measure of job satisfaction may be correlated with work performance. It should be noted that in the simultaneous validity, the two measures are taken at the same time; unlike prediction validity, where there is a first measure that is then used to predict a subsequent measure.
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