TY - JOUR
T1 - Validity of the Control Question Polygraph Test
T2 - The Problem of Sampling Bias
AU - Patrick, Christopher J.
AU - Iacono, William G.
PY - 1991/4
Y1 - 1991/4
N2 - Sampling bias is a potential problem in polygraph validity studies in which posttest confessions are used to establish ground truth because this criterion is not independent of the polygraph test. In the present study, criterion evidence was sought from polygraph office records and from independent police files for all 402 control question tests (CQTs) conducted during a 5-year period by federal police examiners in a major Canadian city. Based on blind scoring of the charts, the hit rate for criterion innocent subjects (65% of whom were verified by independent sources) was 55%; for guilty subjects (of whom only 2% were verified independently), the hit rate was 98%. Although the estimate for innocent subjects is tenable given the characteristics of the sample on which it is based, the estimate for the guilty subsample is not. Some alternatives to confession studies for evaluating the accuracy of the CQT with guilty subjects are discussed.
AB - Sampling bias is a potential problem in polygraph validity studies in which posttest confessions are used to establish ground truth because this criterion is not independent of the polygraph test. In the present study, criterion evidence was sought from polygraph office records and from independent police files for all 402 control question tests (CQTs) conducted during a 5-year period by federal police examiners in a major Canadian city. Based on blind scoring of the charts, the hit rate for criterion innocent subjects (65% of whom were verified by independent sources) was 55%; for guilty subjects (of whom only 2% were verified independently), the hit rate was 98%. Although the estimate for innocent subjects is tenable given the characteristics of the sample on which it is based, the estimate for the guilty subsample is not. Some alternatives to confession studies for evaluating the accuracy of the CQT with guilty subjects are discussed.
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U2 - 10.1037/0021-9010.76.2.229
DO - 10.1037/0021-9010.76.2.229
M3 - Article
AN - SCOPUS:0001639203
SN - 0021-9010
VL - 76
SP - 229
EP - 238
JO - Journal of Applied Psychology
JF - Journal of Applied Psychology
IS - 2
ER -