Running head: THE “THEORIES” OF POLYGRAPH POLYGRA PH TESTING
The “theories” of polygraph testing An Assignment Submitted by Name of Student Name of Establishment Class XXXX, Section XXXX, Fall 2012
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THE “THEORIES” OF POLYGRAPH TESTING The “theories” of polygraph testing Relevant evidence regarding validity of polygraph testing comes from two sources, which are basic scientific knowledge about the processes, which are measured with the help of polygraph and the research that assesses the accuracy of polygraph test. In my opinion, the main source of the evidence relevant to the validity of polygraph testing is basic scientific knowledge. This knowledge tells us about the processes, which are measured with polygraph and the factors that influence such processes. The crucial question is whether a technique can work in practice, whether it can show information about guilty or deceptive individuals that cannot be collected from other techniques known. However, in many situations it can be difficult to determine how well the polygraph works from the scientific point of view. “The appropriate criterion of validity can be slippery; truth is often hard to determine; and it is difficult to disentangle the roles of physiological responses, interrogators’ skill, and examinees’ beliefs in order to make clear attributions of practical results to the validity of the test” (National Research Council, 2003). One of the most essential issues concerning polygraph testing is the well supported theory of the test; because it can provide persuasion that the test will work well as for the efforts which may be made by examinees to produce the negative result, in other words, false. For instance, criminals may be very much motivated to learn how to stay truthful lying about some crimes they committed and to develop new countermeasures to polygraph tests that have not been studied yet. In order to ensure that these measures will fail in case someone wants to use them demands basic understanding of physiological measures which are used in polygraph testing and of the ways they can
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THE “THEORIES” OF POLYGRAPH TESTING reveal themselves under the influence of different intentional activities of those who are examined. It has to be said that theoretical and scientific base is valuable as for the test improvement, because it can recognize the serious threats to the validity of the test and those experiments that should be conducted to prevent such threats. This way, the scientific base is essential for ensuring confidence in the techniques for the psychological detection of deception. Evidence of scientific validity is important to ensure that a test measures the things that are supposed to be measured. This evidence is collected from scientific data on the diagnostic accuracy of a test with certain examiners and examinees. The importance of the evidence of accuracy is that it can show how the test works under certain conditions conditions in which it is applied. However, such evidence is not enough “to give confidence that a test will work well across all examiners, examinees, and situations, including those in which it has not been applied” (National Research Council, 2003). Consequently, we can witness that the test may perform differently in the new situation or with the new population. That’s why it is very frivolous to believe that the result will be only positive or negative. The limitation of accuracy information is extremely serious for polygraph security screening. The target populations, such as terrorists and spies, have not been tested systematically. Confidence in polygraph testing also demands evidence of its construct validity that depends on the theory of the mechanisms that make the test results connected to the phenomenon they are diagnosing.
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THE “THEORIES” OF POLYGRAPH TESTING “A test with good construct validity uses methods that are defensible in the light of theoretical and empirical understanding of those mechanisms that are defensible in light of the best theoretical and empirical understanding of those mechanisms, the external factors that may alter the mechanisms and affect results, and the measurement issues affecting the ability to detect the signal of the phenomenon being measured and exclude extraneous influences” (National Research Council, 2003).
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THE “THEORIES” OF POLYGRAPH TESTING References Committee to Review the Scientific Evidence on the Polygraph, National Research Council. (2003). The Polygraph and Lie Detection. Retrieved from www.nap www.nap.edu .edu
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