The common-item problem in measurement: Effects on cross-cultural invariance of personality inventory structure

A previous study has reported the similarity of the California Psychological Inventory (CPI) structure in American and Israeli samples. In the present paper, however, it is argued that the invariance of structure of the CPI between these two samples may be partially attributable to a common-item effect—that is, the scoring of some items on more than one scale. This common-item effect may superimpose or magnify a similarity of structure. Data analyses supporting this view are presented. It is concluded that a common-item effect in cross-cultural comparison of structure should be considered, otherwise, a similarity of structure between two cultures may be inferred when such a similarity does not exist.