Question

As you know, reliability is a necessary but not sufficient condition for validity. If several clinicians agree with each other about a diagnosis, there is interjudge or interrater reliability. It is possible, however, to have interjudge/ interrater reliability without validity. Explain how this might occur, and illustrate this with a specific example relevant to the field of psychopathology.

Answer 1

Interjudge or interrater reliability occurs when multiple clinicians agree with each other on a diagnosis. However, it is possible to have interjudge/interrater reliability without validity if the clinicians have “inaccurate agreement”. This means that the clinicians are agreeing, but they are all wrong. For example, in the field of psychopathology, a group of clinicians could agree on a diagnosis of Major Depressive Disorder for a patient, when in reality the patient is actually suffering from Bipolar Disorder. In this case, the clinicians have high interjudge/interrater reliability; however, the diagnosis lacks validity since it is inaccurate.