Two dimensional views of adult psychopathology are discussed: (a) the phenomenological view according to which symptoms of psychopathology can occur in normal people in less intense, persistent and debilitating, but not qualitatively different forms; and (b) the vunerability view according to which the degree to which a person possesses the apparent normal counterparts of the symptoms of a psychopathological disorder is an index of that person's vulnerability for the disorder. Examples of research using questionnaires designed by two prominent advocates of these dimensional views, namely, H. J. Eysenck and L. J. Chapman, are reviewed. It is concluded that the research strategies to date do not provide adequate tests of the phenomenological view and provide only weak support for the vulnerability view. Alternative, more direct, research strategies are proposed.