Construct validity in psychological tests

Construct validation takes place when an investigator believes that his instrument reflects a particular construct, to which are attached certain meanings. In the early stages of development of a construct or even at more advanced stages when our orientation is thoroughly practical, little or no theory in the usual sense of the word need be involved. The laws in a nomological network may relate observable properties or quantities to each other, or theoretical constructs to observables; or different theoretical constructs to one another. A necessary condition for a construct to be scientifically admissible is that it occur in a nomological net, at least someof whose laws involve observables. The difficulties in merely &s;characterizing the surface cluster&s; are strikingly exhibited by the use of certain special and extreme groups for purposes of construct validation. Numerous successful predictions dealing with phenotypically diverse &s;criteria&s; give greater weight to the claim of construct validity than do fewer predictions, or predictions involving very similar behaviors.