Individual subject performance during the course of experiments, International Electrotechnical Commission (IEC) standard group and icon group. Here accuracy is depicted in total number of counts (maximum of 16 counts per subject per session). For example, subject 6 in the icon group identified every alarm annunciation correctly (32/32), while subject 1 from the IEC standard group was wrong 26/32 times. Subjects 8, 18, and 20 from the icon group shared the same number of correct counts for sessions 1 and 2; data for these subjects are represented by the same dashed black line. Attg. = attending physician; CA-x = clinical anesthesia year of residency.