Exclusive or Nonexclusive Comparison Questions: A Comparative Field Study
Tuvya T. Amsel · 1999
The relative effectiveness of exclusive (time-bar, or Backster) and nonexclusive (no time-bar, or Reid) probable lie comparison questions (CQ) was assessed by comparing the physiological responses elicited using one or the other type CQ in 230 (60% truthful and 40% deceptive) verified Zone Comparison Test (ZCT) field examinations. Exclusive comparison questions were used in 87 (37.8 %) examinations and nonexclusive comparison questions were used in the remaining 143 (62.2 %). Each examination used two relevant questions and analysis of the field numerical scores showed that overall examinations using nonexclusive comparison questions had significantly larger mean numerical scores (question one, M = 2.99; question two, M = 2.87) compared to examinations using exclusive comparison questions (question one, M = 2.14; question two, M = 2.26). Further analysis showed similar results after computing the mean numerical scores for truthful (NOI) and deceptive (01) subject status. Examinations using nonexclusive comparison questions had scores significantly more in the correct direction than those produced by exclusive comparison questions. These findings are consistent with those reported in some earlier laboratory studies examining the same issue. Together, these results present a strong argument favoring the use of nonexclusive comparison questions, as opposed to exchisive comparison questions, for conducting specific issue POD field examinations.