Abstract: A means for training and testing baggage screening machine operators. The invention is a computer system which causes the baggage screening monitor to show computer-generated (i.e. simulated) contraband items in a piece of baggage. This can be done in one of two ways: the image of the contraband item can be superimposed on the image of an actual piece of baggage being screened so that it appears to be within the piece of baggage, or the image of an entire piece of baggage containing a contraband item can be displayed. The invention allows the operator's proficiency in spotting contraband items to be evaluated and it can be used for training a new operator as well as for providing continued proficiency training and evaluation.