05967123

a

05967123 Yang, Fan Sun, Xianghong Zhang, Kan Zhu, Biyun The number of trials with target affects the low prevalence effect. Harris, Don (ed.), Engineering psychology and cognitive ergonomics. 9th international conference, EPCE 2011, held as Part of HCI international 2011, Orlando, FL, USA, July 9--14, 2011. Proceedings. Berlin: Springer (ISBN 978-3-642-21740-1/pbk). Lecture Notes in Computer Science 6781. Lecture Notes in Artificial Intelligence, 126-131 (2011). 2011 Berlin: Springer EN X-ray luggage screening low prevalence effect miss rate visual search

doi:10.1007/978-3-642-21741-8_15

Summary: Wolfe J M. et al found that subject's miss rate increased markedly when target prevalence decreased in simulated X-ray luggage screening task, which was so-called the low prevalence effect. He thought it was caused by shift of observer's decision criteria. But the number of trials with target (NTT) also affected the effect. The present study had two experiments, and there were two blocks in each experiment. Subjects in Exp 1 were in different NTT (20 vs. 100) but the same target prevalence (both 50\%); In Exp 2, NTT was the same (both 20) but the target prevalence was different (50\% vs. 5\%). The results showed that subject's miss rate was mainly changed with NTT, and decision criteria was up to the target prevalence, Wolfe's conclusion was not completely correct.