The Supreme Court of New Hampshire issued an opinion in the case of Baxter v. Temple (#2007-102) yesterday involving the admissibility of the Boston Process Approach (BPA) of neuropsychological assessment. In brief, the BPA is a widely used assessment approach used by neuropsychologists which utilizes a priori selection of psychological tests instead of the full battery of tests used in other assessment approaches. As the Court stated:

While the BPA itself does not have a known or potential error rate, the Daubert factors “do not constitute ‘a definitive checklist or test’” that must be applied in all circumstances. Kumho Tire, 526 U.S. at 150 (quoting Daubert, 509 U.S. at 594); see also RSA 516:29-a, II. Rather, the factors must be applied with flexibility and in light of the proffered testimony. Baker Valley, 148 N.H. at 616. Given the nature of the BPA, and particularly that it inherently requires some level of flexibility, we find that the known or potential error rate factor is not an “appropriate” consideration in examining its reliability. See RSA 516:29-a, II(a).

However, we note that a critical component of our finding that the BPA meets three of the four Daubert factors is the use of standardized tests. To meet the threshold for reliability, a neuropsychologist applying the BPA must demonstrate that the individual tests he or she administered as part of the battery, not the battery as a whole, have been tested, have been subject to peer review and publication, and have known or potential error rates. Cf. United States v. Eff, 461 F. Supp. 2d 529, 531, 533 (E.D. Tex. 2006)

The opinion is an interesting, albeit somewhat technical, read for anyone with a curiosity about the various tests often used in neuropsychological assessment.