The Scientific Basis Of Psychological Testing: Considerations Following Daubert, Kumho, and Joiner

Abstract

The legal standards for admissibility of expert testimony have recently been raised following several U.S. Supreme Court decisions. Although forensic mental health experts have reiied on psychological testing as a method of data collection for many years, the scientific basis of such testing has traditionally gone unquestioned in court. Given the increased scmtiny currently being applied to expert testimony, it is more important now than ever for attorneys, judges, and forensic experts to understand the scientific principles underlying psychological tests. In this article, the scientific principles of validity and reliability are explained, and scientifically acceptable methods for the forensic use of psychological testing are discussed. The application of recent case law to several well-known tests is described.

Does the R-PAS Meet Standards for Forensic Use? Considerations with Introducing a New Rorschach Coding System

“…Erard primarily frames his argument around the Rorschach method itself, writing, "It seems reasonable to suppose, consistent with the experience of many forensic psychologists, that most courts have limited interest or patience in disentangling fine technical points such as the comparative advantages of two quite similar assessment systems such as R-PAS vs. the CS" (p. 128). Working from this premise, Erard reviews the large body of research pointing to the general acceptance of the Rorschach that has been held up by previous authors analyzing the admissibility of the CS under Frye (e.g., McCann & Evans, 2008;Meloy, 2008;Medoff, 2003;Ritzler et al, 2002aRitzler et al, , 2002b.…”

“…and (d) Is the technique or methodology generally accepted in the scientific community? (Medoff, 2003). The Court clearly states in Daubert not only that consideration of these factors is flexible but that the focus of any relevant analysis should remain solely on the principle and methodology in question, not the conclusions rendered from them.…”

“…Citing survey research pertaining to clinical training programs as well as clinical and forensic practitioners, McCann and Evans (2008) reach the conclusion that the CS Rorschach is indeed generally accepted in the relevant community. Further, many peer-reviewed published articles identify the CS Rorschach as a widely used assessment measure in the field of personality assessment (e.g., Medoff, 2003;Ritzler et al, 2002b;Rose, Kaser-Boyd, & Maloney, 2001;Weiner, 2005). Seventh, both the FRE and Daubert require that testimony be relevant and helpful.…”

Protecting the Integrity of Forensic Psychological Testing: A Reply to Geffner, et al. (2009)

“…The practice of forensic psychology in general, and forensic psychological testing specifically, clearly requires a higher standard of practice than that necessary for clinical work (APA, 1994;2009;Association of Family and Conciliation Courts, 2006;Bow et al, 2006; Committee on the Revision of the Specialty Guidelines for Forensic Psychology, 2006;Flens & Drozd, 2005;Hamilton, 1998;Heilbrun, 1992;Koocher, 2006;Medoff, 2003;Otto & Heilbrun, 2002;Perrin & Sales, 1994). These higher standards are not only demonstrated by the designation of forensic practice as a specialty, but they also arise from the United States Supreme Court decisions of Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993), General Electric Co. v. Joiner (1997), and Kumho Tire Co. v. Carmichael (1999.…”

“…In so doing, however, they violate fundamental and established tenets of forensic psychological assessment by recommending the forensic use of several subjectively based, invalid, and scientifically unreliable psychological techniques including the Thematic Apperception Test (TAT), the Roberts Apperception Test for Children, the Sentence Completion Test (SCT), the Draw-A-Person technique (DAP), and Kinetic Family Drawings (e.g., Ackerman, 1999;American Psychological Association, 2009;Bow, Gould, Flens & Greenhut, 2006;Gould, 2005;Gregory, 2007;Heilbrun, 1992;Khan & Taft, 1983;Medoff, 2003;2009;Melton, Petrila, Poythress, & Slobogin, 2007;Otto & Heilbrun, 2002;Weithorn, 2006;Wrightsman, 2005).…”