PSY 330 Human Factors
5/1/00
Day 2-8
Human Error Probability
uError Probability (EP) also known as Human Error Probability (HEP): 
lEP = (# of errors)/(total # of opportunities for the error)
lvalue between 0 and 1
lgives rate of errors
lthis is a probabilistic value
uit does not indicate if an error will or will not occur
ujust the likelihood
ldoes not indicate type or cause of error