Equations for prorating the symptom validity scale (FBS) for the 370-item MMPI-2

The Symptom Validity Scale (FBS), based on the 567-item form of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), has been shown to be a valid measure of symptom over-reporting. To extend its usefulness to the 370-item form, complete FBS scores (FBS) and FBS scores based on the 370-item form (FBS-S) were extracted from 707 protocols from various testing contexts. Regression analyses using the FBS-S score were developed to predict FBS scores. Results indicate that the full FBS score can be accurately prorated from the FBS-S. Calculated coefficients based on FBS-S score were slightly, but not meaningfully, better than a rationally derived proration in estimating the full FBS score.