According to the equating guidelines, a set of common items should be a mini version of the total test in terms of content and statistical representation (Kolen & Brennan, 2004). Differences between vertical scaling and equating would suggest that these guidelines may not apply to vertical scaling in the same way that they apply to equating. This study investigated how well the guideline of con...

Estimation of premorbid abilities remains an integral part of neuropsychological evaluations. Several methods of indirect estimation have been suggested in the literature. Many of these methods are based in prediction via linear regression. Unfortunately, linear regression has the well-reported tendency to underpredict high IQ scores and overpredict low IQ scores. This can be shown to be an una...