Summary: | 碩士 === 國立臺北大學 === 犯罪學研究所 === 99 === Based on the concept of 「Fear of detection」,「Psychological Set」and 「Conditioning」, the research is trying to design a 「Screening Question Set」. By evaluating the Verbal Behavior, the author attempted to access the feasibility of「Pre-Polygraph Examination Screening Instrument(P.E.S.I.)」. So the purpose of the research is to define the optimal cut-off value of this question set, to determine the degree of accuracy, the discrimination between every single question and the affection of different population variables.
From November 2010 to February 2011, the research sample had collected all examinees who applied by the judiciary to the Criminal Investigation Bureau. After questioning the 「Screening Instrument」by the polygraph examiners, the author should evaluate the responded content obtained from the examinees and score it.
The result shown that the score of the 「Screening Instrument」in the 「deception Indicated group」(0.13)is significantly lower than that in the「Non-Deception indicated group」(0.52). It means the 「Screening Instrument」really can distinguish the truth from lies. After that, by using the 「Receiver Operating Characteristic curve」, it is shown that the optimal cut-off value of the score is 0.32456, and the predictability expressed as the area under the curve (AUC) of the receiver operator characteristic curve (ROC) was 0.901. Supposed comparing with the polygraph conclusion, the total consistency rate was 83.65% and the positive and negative predictive value was 82% and 85.2%. In addition, every single question in「Screening Instrument」contributes a different degree of discrimination. It could be implied that the「Screening Instrument」can be optimized by choosing 「Good」questions. Finally, the research also showed that the differences between gender, age, education and status did not affect the results.
The author believed that by using「Pre-Polygraph Examination Screening Instrument(P.E.S.I.)」, the examiner can get an initial conclusion about whether the examinee was lying before Polygraph Examination. The research confirmed this opinion.
The findings also considered that the 「Pre-Polygraph Examination Screening Instrument(P.E.S.I.)」, in conjunction with a carefully controlled procedure, could be used to prioritize suspects. It assists to relieve the heavy workload of polygraph examination. Furthermore, using the「Pre-Polygraph Examination Screening Instrument(P.E.S.I.)」can help the examiner notice wider aspects of the Polygraph Examination itself, avoiding unnecessary errors.
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