Forensic, General & Medical
Expert Witnesses

Selecting Psychological Tests and the Experts Who Testify


Expert Witness: Steven N. Shapse, Ph.D.
When deciding upon an expert one might want to consider the following questions:

• Has the expert ever testified before? How many times?
• How does the expert present in court? Is he well organized and is his thinking logical and easy to follow?
• Is he a member of major professional organizations?
• Does he employ well-known and generally accepted psychological tests?

When deciding upon an expert one might want to consider the following questions:

• Has the expert ever testified before? How many times?
• How does the expert present in court? Is he well organized and is his thinking logical and easy to follow?
• Is he a member of major professional organizations?
• Does he employ well-known and generally accepted
FIND MORE ARTICLES
psychological tests?
• In specialty areas such as child custody, trauma, personal injury, and PTSD, does he use local or specialize norms? Does the expert know how to interpret the results within the context of these special circumstances?

When considering employing psychological tests in forensic situations a number of factors must be taken into account including Daubert standards. These include:

• Is the instrument a frequently used clinical test?

• Is the inventory relatively easy to administer and score?

• Is the administration of the test monitored?

• Does the instrument contain validity measures? Is it possible to differentiate fake good from fake bad responding? Can response bias be corrected for conscious manipulation?

• Is interpretation objective? Is interpretation normed-based? Is the test normed for the population in question? Are interpretations of findings valid to people's problems symp-toms and characteristics? Can they be presented in a clear and understandable manner?

• Does the instrument have high validity and reliability?

• Are results reproducible on retest?

• Can findings be used to predict future behavior and direct treatment, (if treatment is indi-cated)?

• Are findings easy to explain in court to allay population?

The expert must not only be versed in the assessment instruments themselves, but knowledgeable as well as to the ethical standards under which they operate.
• Psychologists are bound by APA’s Ethical Principles of Psychologists and Code of Con-duct.
• Does the expert rely on scientifically and professionally deduced knowledge?
• Are the assessment instruments and associated methodology or appropriate for the tasks in which they are employed?
• Is the expert familiar with the psychometric properties and limitations of the instruments employed and is he able to testify to the limitations of such tests?

Look for the utilization of these commonly employed tests:
Minnesota Multiphasic Personality Inventory- 2
The MMPI-2 is probably the most commonly used and well-researched personality tests in use today.

Millon Clinical Multiaxial Inventory (MCMI, MCMI-II & MCMI-III)
Despite controversies surrounding this instrument, it is commonly used and widely accepted.

Rorschach Ink Blot Test (Exner Comprehensive System)
This instrument has been widely accepted by courts across the country. It does have its critics. However in only one case was Rorschach testimony excluded by the trial court.

Wechsler Intelligence Tests
These include tests for preschoolers, grade school children and adults. They are the most widely used and accepted tests of intelligence and cognitive functioning.

When the expert testifies in court, the admissibility of behavioral evidence will be enhanced by the following:
• Present qualifications as to education, training, and experience that are pertinent to the matter at hand.
• Demonstrate the necessary knowledge and familiarity with the literature relevant to the specific case especially that which supports the expert’s opinion.
• Present in a factual and precise manner.


SELECTED BIBLIOGRAPHY

Choca, James P. (2004). Interpretive Guide to the Millon Clinical Multiaxial Inventory, 3rd Ed. Washington, DC:American Psychological Association.

Craig, Robert J. (1999). Interpreting Personality Tests: A Clinical Manual for the MMPI-2, MCMI-III, CPI-R, and 16PF. New York:John Wiley & Sons, Inc.

Friedman, Alan F., et al (2001) Psychological Assessment with the MMPI-2. Philadelphia, PA:Lawrence Erlbaum Associates.

Gacono, Carl B. and Evans, F. Barton, eds. (2008). The Handbook of Forensic Rorschach As-sessment. Philadelphia, PA:Lawrence Erlbaum Associates.

Kaufman, Alan S. and Lichtenberger, Elizabeth O. (2006). Assessing Adolescent and Adult Intel-ligence, 3rd Ed. New York:John Wiley & Sons, Inc.



ABOUT THE AUTHOR: Steven N. Shapse, Ph.D.
Dr. Steven N. Shapse is a Licensed Psychologist in the Commonwealth of Massachusetts. He has over 30 years experience in the field of psychology as both a clinician and teacher which in-cludes over twenty years as a forensic expert, psychometrist and child custody evaluator. He regularly presents at state and national associations, and often teaches at the Massachusetts School of Professional Psychology. He is a Senior Supervisor at the Justice Resource Institute Trauma Center and a principal founder and Past-President of the Massachusetts Association of Guardians ad Litem.

Copyright Steven N. Shapse, Ph.D.
More information about this article at Steven N. Shapse, Ph.D.

Disclaimer: While every effort has been made to ensure the accuracy of this publication, it is not intended to provide legal advice as individual situations will differ and should be discussed with an expert and/or lawyer.For specific technical or legal advice on the information provided and related topics, please contact the author.

Find an Expert Witness