Success (n), define.

Story in the papers over the weekend about the intention to use airport-style scanners at tube and railway stations to detect people carrying knives. This follows a trial of such measures in London which the Transport Secretary described as "extremely successful". Statistics published show that some 10,000 people were scanned, 68 knives were seized and 100 people arrested - presumably some for reasons other than carrying knives. So 1% arrests and less than 1% where knives were discovered. Obviously it's better than nothing, but given that this was targeted and not random scanning, I would hardly describe such a result in such glowing terms.