WAIS-IV false positive rates, likely influenced by racial/ethnically correlated variables of years of education, bilingualism, and qualitative aspects of education, were significantly lower for the México than the U.S. versions across all cut-scores. They were significantly reduced for both versions and all cut scores by using a performance-based estimate of preexisting skill level versus the normative 50th percentile.
Ontiveros et al. (Fri,) studied this question.