Terms Relating to Lie Detectors Explained – Letter D
- Daubert V Merrell Dow Pharmaceuticals, Inc.
- Although not a PDD case, the Daubert case set aside the Frye Rule’s “general acceptability” provisions in favor of the Federal Rules of Evidence. The case paved the way for the admissibility of PDD evidence in most jurisdictions. The Daubert standard is a rule of evidence regarding the admissibility of expert witness testimony. Essentially it states that the judge is gatekeeper and determines what gets into evidence. The judge determines if it is relevant to this case and reliable. The judge also decides whether the evidence is based on scientific knowledge or methodology: falsifiable, refutable, and testable; subjected to peer review and publication; known or potential error rate; existence and maintenance of standards and controls concerning its operation, and; degree to which the theory and technique is generally accepted by a relevant scientific community. See: Daubert v Merrell Dow Pharmaceuticals, Inc. (1993).
- Deception
- The act of deliberately providing or omitting information with the intention of misleading. The most critical element of the definition is the intention of the information provider. With no intent, deception does not take place regardless of the accuracy of the information being conveyed. For example, in early history humans misunderstood the nature of the solar system, but they were not deceiving when they taught a geocentric universe. Conversely, deception takes place when there is the intent, even if the speaker unwittingly conveys correct information. This is an important concept to consider with regard to PDD. Inconsistencies between ground truth and examinee beliefs may erroneously appear to be mistakes of the PDD technique. One of the great challenges of analog PDD studies is inducing an experiment volunteer to believe he is intending to deceive the examiner rather than merely obeying instructions.
- Deception Exemplar
- Physiological response pattern which examinees expect to be used as a sample, or exemplar, of that which occurs when they are deceptive, and will be used for comparison against their responses to relevant questions. See: Matte (2000).
- Deception Indicated (Di)
- Along with NDI (No Deception Indicated) and Inconclusive, a conventional term for a polygraph outcome. A decision of DI in PDD means that (1) the physiological data are stable and interpretable, and (2) the evaluation criteria used by the examiner led him to conclude that the examinee is not wholly truthful to the relevant issue under investigation. The DI and NDI decision options are used primarily in single-issue testing, and they correspond with SR (Significant Response) or SPR (Significant Physiological Responses) and NSR (No Significant Response) or NSPR (No Significant Physiological Responses) in multiple-issue, or screening, examinations with the US Government.
- Deception Test
- These methods ask directly about the matter to be assessed, are capable of addressing multiple behavioral issues of concern and may or may not depend on the existence of a known incident or known allegation. There are two broad categories of deception tests, the historically older Relevant- Irrelevant and the Comparison Question Tests (CQT). Term is used in contrast to recognition test.
- Decision Rule
- Generically, decision rules determine when data meet the criteria for inclusion in a particular category. Decision rules are the final steps in polygraph numerical scoring, producing categorical classifications. Optimal decision rules require the following: tracing feature selection; development of best scoring rules, consideration given for base rates; assessing and weighting collateral or countervailing information, and; performance of a cost and benefit analysis to determine the achievable level of accuracy and errors that meet the needs of the consumer. In polygraphy, feature selection and scoring rules have been thoroughly investigated. There are also decision rules in some polygraph analysis systems that include extra-polygraphic information as part of the decision process, though there is no validated method yet published. However, few published decision scoring procedures allow for consideration of the base rate issue. Also, few models publish a sufficient level of detail to allow a formal cost-benefit analysis to identify the appropriate cutting scores for a set of conditions. See: Swets, Dawes & Monahan (2000).
- Defensible Dozen
- Expression used to connote the 12
- Degrees Of Freedom (Df)
- For any set of values, every value within a set can be freely selected except the last, which is determined. Or, in other words, when there is only one value remaining, the final selection is not free to vary. Technically, the concept of degrees of freedom refers to the number of independent observations minus the number of parameters being estimated. The degrees of freedom are essential in the calculation of the threshold or critical value of a test distribution.
- Delayed Answer Test (Dat)
- Experimental methodology used to determine whether physiologic responding was elicited by the stimulus question or an untruthful answer. It was experimentally demonstrated that the physiological arousal was more closely tied to the stimulus presentation than the act of giving the deceptive answer. The DAT is not used in field PDD examinations. See Dawson (1980).
- Dendrite
- Process of a neuron specialized to function as a postsynaptic receptor region of the neuron.
- Department Of Defense Polygraph Institute (Dodpi)
- See National Center for Credibility Assessment.
- Dependent Variable
- Variable that changes as a result of the experimenter’s manipulation of the independent variable. For example, electrodermal activity could act as a dependent variable to changes in stimulus intensity, an independent variable.
- Devil’s Finger
- See finger of death.
- Diagnostic And Statistical Manual Of Mental Disorders, 4th Edition
- The official system for classification of psychiatric and psychological disorders prepared and published by the American Psychiatric Association in June 2000. Abbreviated as DSM-IV-TR.
- Diastole
- Portion of the heartbeat cycle when the heart muscles have relaxed and the chambers fill with blood. The left ventricular diastole is represented in the PDD sphygmograph tracing as the descending limb of the pulse wave (catacrotic limb).
- Diastolic Blood Pressure
- Lowest blood pressure value occurring during the relaxation phase of the cardiac cycle.
- Dichotomization Theory
- A hypothesis that holds there is a difference in habituation rates for relevant and comparison question responses. According to this theory, guilty subjects habituate more slowly to relevant questions, while innocent examinees continue to respond more strongly to the comparison questions over time. Dichotomization theory has not been generally accepted in PDD. See: Ben- Shakhar, G. (1977).
- Dichotomous Variables
- Those for which there are only two mutually exclusive and exhaustive possibilities: male or female, yes or no, 0 or 1, heads or tails, etc.
- Dicrotic Notch
- A regular feature in diastolic limb of the pulse wave recorded on the sphygmograph of the polygraph. It occurs between the systole and subsequent diastole of the waveform, and its proximity to either of these two cardiac events is a function of the air pressure in the recording system. The greatest contributor to the dicrotic notch is the rebounding of the blood against the closed aortic semilunar valve after systole. It has not been found to be a reliable diagnostic feature in PDD. Also called incisura.
- Differential Responsivity (Reactivity)
- Term frequently reported in PDD literature regarding the differences in responses to two types of questions. In Comparison Question Technique (CQT) formats, differential responsivity (differential reactivity) relates to the relative response magnitudes from relevant questions as compared to those from comparison questions. Within normal limits, this differential responsivity (reactivity) persists even when overall responsivity is attenuated, or as it habituates. For this reason, CQT formats are unlikely to render false negative decisions that are attributable to countermeasures that attack general arousal, such as the use of drugs, relaxation, or dissociation. By contrast, the Peak of Tension and Concealed Information Tests rely on differential responsivity (reactivity) between critical and neutral items. Decisions in these concealed information tests are based, not on the type of question that induces the response, but rather the presence or absence of significant responses to the critical items only. Therefore, the type of differential responsivity used in decision making in PDD, along with vulnerability to certain types of countermeasures, will depend on the polygraph technique.
- Differential Salience
- Expression that characterizes the positive correlation between the degree of psychological significance and intensity of the physiological response. The concept of differential salience is based on the premise that responsivity can reveal underlying mental processes which can be exploited to detect deception or recognition under controlled and structured conditions. It does not restrict the operating mechanism to fear, but assumes a common pathway for the physiological expression of those cognitive and emotional processes that gave rise to the psychological salience. It is proposed as a substitute for the older “Psychological Set” hypothesis. See: Handler & Nelson (2007); Handler, Shaw & Gougler (2010); Senter, Weatherman, Krapohl & Horvath (2010).
- Directed Lie Screening Test (Dlst)
- A screening test for law enforcement based on the technique and procedures for the Test for Espionage and Sabotage (TES). The DLST uses a repeated series of two relevant and two directed-lie comparison questions, and the conventional 7-position scoring system. See: Blalock (2009); Handler, Nelson & Blalock (2008). Reed (1994); Research Staff (1995,1998).
- Directed-Lie Comparison (Dlc) Question
- Type of question used to elicit a response that is compared with the response evoked by the relevant question. The DLC question is different from the probable-lie comparison (PLC) question in that the examinee is instructed by the examiner to answer the DLC question untruthfully, whereas the principle of the PLC requires the examiner to lead the examinee to be untruthful to that question without revealing the purpose. DLCs can be further delineated into the trivial DLC and the personally significant DLC, which, as their names indicate, depend on the content of the DLC. The true strengths of the DLCs are that they can be standardized much easier than the PLCs, they are less intrusive, and their effectiveness is less subject to examiner skill. DLCs are being used in many quarters of the PDD profession. See: Horowitz, Kircher, Honts, & Raskin (1997); Raskin & Honts (2002).
- Disclosure Examination
- See sexual history examination.
- Discontinuous Blood Pressure Method
- Deception test procedure developed by William Marston before 1915. Marston’s instrumentation was a standard sphygmomanometer that he used to take intermittent systolic blood pressure measurements during questioning on relevant and irrelevant topics. He plotted these measurements by hand, creating a curve that was interpreted for assessing deception. In 1923 Marston attempted to have the results of his deception test entered into evidence in a murder trial in Washington, DC. The Frye case, which was the first to consider deception tests, established the precedent for exclusion of “lie detector” results. The discontinuous blood pressure method did not enjoy widespread field acceptance, and there are no reports of its use after the 1930s. In the 1920s William Marston included a cardio-pneumo polygraph to augment his discontinuous blood pressure method. In practice, Marston and his wife, Elizabeth, would either ask the examinations questions or take the blood pressure measurements, while Olive Richard, an assistant, operated the equipment. If a stenographer were present, there were four participants in the administration of the examination in addition to the examinee. While William Marston was usually the examiner, Elizabeth Marston and Olive Richard did conduct examinations on occasion without him, making them the first women in this field. Given the great methodological and instrumentation differences, Marston discontinuous blood pressure method is not truly in the lineage of modern polygraphy, though it is frequently included in history lessons at polygraph schools. See: Marston (1917; 1938).
- Discovery Test
- See disclosure test.
- Discriminant Analysis
- Regression analysis with a categorical criterion—that is, attempting to predict group membership from one or more predictor variables. The CPS algorithm is based on discriminant analysis.
- Disguised Comparison Question
- Comparison questions that are designed to be difficult to identify as such. Typically used in multiple-issue screening examinations. For example, the examinee might have the following disguised comparison question: Did you ever cheat in school? It is expected that nearly every examinee would have doubts about the integrity of his entire academic career, and also believe that truthfulness on the question is required to pass the polygraph examination. Sometimes call hidden comparison question.
- Dissociation
- Psychologists use the term dissociation to denote largely unconscious processes by which normal relationships in thought, memory, attitudes, or other psychological activities do not adhere to their established relationships and become separate or independent. It is also used in PDD to characterize the deliberate disengagement of attention by examinees from the testing situation. Such tactical redirection of attention is considered a mental countermeasure. Examinees who use this approach are hopeful that they may eliminate physiological responding by virtue of their mental distance from the test questions. Dissociation may be effective in test formats where examinees respond with the same answer to each question, such as with the Peak of Tension. In that format the examinee needs only listen for the point when the examiner stops speaking, and give the rote answer. Dissociation is considered a more unlikely countermeasure for those formats that require both yes and no answers, and where the order of the questions is not predictable to the examinee, or where examinees are required to use key words from the test question in the answer. See: Elaad & Ben-Shakhar (1991); Kircher, Woltz, Bell & Bernhardt (2006).
- Domestic Violence Offender Testing
- A program intended to incorporate the polygraph in an attempt to verify compliance with the conditions of probation for convicted domestic violence offenders. As with post-conviction sex offender testing (PCSOT) and intoxicated drivers on probation (IDOP), it is designed to contribute to community safety by detecting and discouraging behaviors that pose a threat to the public by individuals with a demonstrated propensity to engage in certain criminal acts.
- Double Verification Test
- Alternate term for card test. See stimulation test.
- Dyspnea
- Labored or difficult breathing, generally resulting from disease.
