This study was designed to expand on a recent meta-analysis that identified ≤42 as the optimal cutoff on the Word Choice Test (WCT). We examined the base rate of failure and the classification accuracy of various WCT cutoffs in four independent clinical samples (N = 252) against various psychometrically defined criterion groups. WCT ≤ 47 achieved acceptable combinations of specificity (.86-.89) at .49 to .54 sensitivity. Lowering the cutoff to ≤45 improved specificity (.91-.98) at a reasonable cost to sensitivity (.39-.50). Making the cutoff even more conservative (≤42) disproportionately sacrificed sensitivity (.30-.38) for specificity (.98-1.00), while still classifying 26.7% of patients with genuine and severe deficits as non-credible. Critical item (.23-.45 sensitivity at .89-1.00 specificity) and time-to-completion cutoffs (.48-.71 sensitivity at .87-.96 specificity) were effective alternative/complementary detection methods. Although WCT ≤ 45 produced the best overall classification accuracy, scores in the 43 to 47 range provide comparable objective psychometric evidence of non-credible responding. Results question the need for designating a single cutoff as "optimal," given the heterogeneity of signal detection environments in which individual assessors operate. As meta-analyses often fail to replicate, ongoing research is needed on the classification accuracy of various WCT cutoffs.
Keywords: Word Choice Test; optimal cutoffs; performance validity.