Abstract
Studies on human errors as psycho-physiological phenomena were reviewed and discussed. Physiological background conditions as shift of working state, fatigue, lowered physiological level or concentration of attention as well as environmental conditions play essential roles in error commission. The process how an error may be induced and thus lead to an accident should be classified into four cases: insufficient input informations, modification of input perception, lowered cortical function and improper output performance. As ergonomic measures for prevention of errors attention should be drawn to such factors as aptitude of workers, sufficient inputs and their visibility and audibility, false reading, direction of operation or the memory time and others.
