What is Convergent validity

Convergent validity is the extent to which scale correlates positively with other measures of same construct. It isn't essential that all these measures be attained by using conventional scaling techniques. Discriminant validity is the extent to which a measure doesn't correlate with other constructs from which it's supposed to differ. It includes demonstrating a lack of correlation among differing constructs. Nomological validity is the extent to which scale correlates in theoretically predicted ways with measures of different however related constructs. A theoretical model is formulated that results in further deductions, tests and inferences. Gradually, a nomological net is built in which various constructs are systematically interrelated.