Standardized Polygraph Test – Polygraphers – Polygraph Relevant Questions – Polygraph Examinations Expert Witness



Polygraph 102 – An Outline An article by Kenneth E. Blackstone A standardized test presents a standardized set of questions or other stimuli (such as images) under generally standardized conditions; responses from the individual are collected in a standardized format and scored and interpreted according to certain standardized norms or criteria. The basic idea is that all individuals who take the test take the same test under the same conditions and the responses are subsequent to a controlled and therefore identifiable stimulus. In a polygraph test the stimuli are limited to questions. Obviously, not all aspects of all tests are exactly equivalent. One individual may take the test during the day in a large room; another may take the test at night in a small room. The assumption is, however, that in all essential respects (those that might significantly affect test performance), all individuals are taking the "same'' test. Because characteristics of the individual taking the test or the testing circumstances may significantly influence interpretations and resultant responses, examiners are responsible for the identification and avoidance of contaminating stimuli. As in most popular tests, systematic investigations of polygraph have indicated which factors need to be taken into account so that extraneous or confounding factors do not distort the results. As a result, polygraphers draw from validated principles and perform examinations using validated techniques. Of these validated principles, the construction of questions is of great importance. In a polygraph test, the stimuli are limited to pre-reviewed questions and they are presented several times based on the format used. Questions asked about the issue-at-hand, what polygraphers define as “Relevant” questions, must be clear, explicit, unambiguous and open to only one reasonable interpretation. The specificity or accuracy of a polygraph examination increases as the scope of the Relevant question decreases and the scope is based on the time of reference and the theme of reference. For example: Did you shoot that man in that parking lot (theme) on Saturday, February 2nd, 2008 (time)? See the article: Polygraph 101. Kenneth E. Blackstone is a certified polygraph examiner and expert witness regarding the proper use of polygraph in civil, clinical and criminal testing settings concerning polygraph procedures used in the evaluation of accusations of rape, kidnapping, homicide, child abuse, molestation, sexual harassment, and shaken baby syndrome, and during sex offender management and civil commitment proceedings. He has been involved in more than 23,000 polygraph examinations and has conducted more than 15,000 polygraph examinations. Download a PDF version of this article. Home \| Clients \| Credentials \| Articles \| Contact Copyright © 2007-08 Kenneth E. Blackstone, All Rights Reserved. Site composition by Expert Communications Website Design by Jenny Duarte	Attorney Comment: “I was a guardian ad litem; I read his report and heard his testimony and have used Ken since then on everything.” Prosecutor Comment: “Your testimony was some of the best I've heard as a prosecutor, and your objectivity restores my faith in polygraph.”