An attempt to provide understandable and up-to-date information regarding intelligence testing, intelligence theories, personal competence, adaptive behavior and intellectual disability (mental retardation) as they relate to death penalty (capital punishment) issues. A particular focus will be on psychological measurement, statistical and psychometric issues.
Wednesday, May 18, 2011
FYiPOST: The curious story of 'a reasonable degree of professional certainty'
I recently had a strange experience: An opposing attorney made a motion to exclude my report in a legal case, because I had not written that I held my expressed opinions "to a reasonable degree of psychological certainty." The attorney who had retained me was forced to scramble to obtain a written declaration from me, stating that I did indeed hold my opinions to this level of certitude. I typically do not include this magic phrase in reports, finding it rather obtuse and, frankly, pompous-sounding. So, when my colleague Dr. Worthen expressed knowledge of the phrase, I prevailed upon him to write this guest post.
Guest post by Mark D. Worthen, Psy.D.*
Expert witnesses who testify based on their medical, psychological, or other scientific training and expertise, are often asked to express their opinions "to a reasonable degree of medical (or psychological or scientific) certainty." But what does this phrase mean and why is it used in legal proceedings?