The human factor in inspection

One of the major justifications for implementing machine vision inspection is that computers are much better than people at performing inspection. The human mind tends to wander, which is why parts with glaring errors or defects still get past end-of-line inspection.

And this is why, with a nod towards topical matters, I was interested in this article on the BBC web site, “Would you trust the human eye to spot a bomb?”

The point writer Chris Yates makes is that security screening equipment is only as good as the people who look at the images. You could have the best explosive detector in the world, but if the guy looking at the screen has been on duty six hours what are the chances of him catching a positive indication? More than likely, his eyes will have glazed over and he’ll scarcely know what’s being displayed.

Inspection is a crappy job for a human to do, because we are not able to maintain constant vigilance. This is why I’d be happier if the scanner images were analyzed by software, with suspicious indicators being flagged for human review.

A few false positives are preferable to one false negative.