The over-claiming technique was designed by Paulhus and Bruce (1990) as an unobtrusive measure of both intelligence and self enhancement bias. Participants rate their familiarity with persons, events, and things on a 5-point scale (1 = never heard of it, 5 = completely familiar). Some of these items do not exist; responses greater than 1 for such items suggest overclaiming of knowledge. The use of a 5-point scale, as opposed to a simple "yes-no" response system, facilitates the collection of more detailed information (i.e., ROC curves).

       Signal detection formulas are then used as indexes of accuracy and bias. Knowledge accuracy is assessed by the participant's ability to distinguish real items from fictitious items ("foils"), whereas self-enhancement is assessed by the overall tendency to claim familiarity with items. Much of the early research used a 150-item Over Claiming Questionnaire (OCQ-150).

       An extensive program of research has confirmed the value of the over-claiming technique. One recent paper presents four studies highlighting the performance of the OCQ bias measure as a measure of self-enhancement (Paulhus, Harms, Bruce, & Lysy, 2003). Another paper presented four studies highlighting the performance of the accuracy index as a measure of general cognitive ability - primarily crystallized intelligence (Paulhus & Harms, 2004). Use items with one- or two-word terms places less of a cognitive burden on the subject (e.g. as opposed to a lengthy multiple-choice item), which then facilitates quicker and more valid responding. In a recent study, we were able to administer three times as many OCQ items as multiple-choice items in a shorter amount of time. Furthermore, the OCQ was a better predictor of external criteria, such as course performance and IQ, than a parallel multiple-choice test (Nathanson, Paulhus, & Williams, 2003).

       The original OCQ-150 focused primarily on knowledge in a variety of academic areas. Since then, we have also developed versions to measure knowledge in non-academic domains (e.g. fashion, sports, television, etc.). Knowledge accuracy always correlates positively with IQ; Knowledge bias correlates positively with narcissism only if the knowledge domain is valued by the respondent. Two recent chapters summarize our latest work on overclaiming (Paulhus & Holden, 2010; Paulhus, in press).