It has been said that experience is that mental faculty which enables us to recognize a mistake when we make it again. We were reminded of that during a recent discussion about the successful deployment of vending machines and changers that accept larger banknotes and pay back smaller ones.

In the wake of the election, one topic that has received a good deal of discussion is the growing inability of exit polls to deliver an accurate picture of what voters actually are doing. Citizens have become adept at expressing views that they regard as acceptable to their peers, and reserving their own opinion for the voting booth.